Gr 8 Natural Sciences Term Test 3

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Questions and Answers

What is responsible for the resistance against the movement of an object resulting from its contact with another object?

  • Neutrons
  • Protons
  • Friction (correct)
  • Electrons

What happens to an object when it loses electrons due to friction?

  • It becomes neutrally charged
  • It becomes positively charged (correct)
  • It remains unchanged
  • It becomes negatively charged

What is the normal state of an atom?

  • Neutrally charged (correct)
  • Unstable
  • Positively charged
  • Negatively charged

What is the result of two objects with opposite charges coming together?

<p>They attract each other (A)</p> Signup and view all the answers

What is the charge of neutrons?

<p>No charge (C)</p> Signup and view all the answers

What is the cause of static electricity?

<p>Electrons transferring from one object to another (C)</p> Signup and view all the answers

What happens when two objects with the same charge interact?

<p>They repel each other (B)</p> Signup and view all the answers

What is the result of combing your hair with a plastic comb?

<p>Your hair stands on end and produces crackling sounds (C)</p> Signup and view all the answers

What is the primary function of a battery in a circuit?

<p>To provide energy for the current (A)</p> Signup and view all the answers

What happens to the flow of current when a switch is open?

<p>The current stops flowing (B)</p> Signup and view all the answers

What is the purpose of a light bulb in a circuit?

<p>To act as a load and convert electrical energy into light energy (C)</p> Signup and view all the answers

What is the difference between a series circuit and a parallel circuit?

<p>A series circuit has a single path, while a parallel circuit has multiple paths (C)</p> Signup and view all the answers

What is the purpose of a resistor in a circuit?

<p>To convert electrical energy into heat energy (B)</p> Signup and view all the answers

What is represented by a pair of parallel lines in a circuit diagram?

<p>A cell or battery (A)</p> Signup and view all the answers

What happens when a component fails in a series circuit?

<p>The entire circuit is broken (D)</p> Signup and view all the answers

What is the function of wires in a circuit?

<p>To conduct current between components (C)</p> Signup and view all the answers

What is the rating for AAA, AA, C, and D cells?

<p>1.5V (C)</p> Signup and view all the answers

What is the unit of measurement for resistance?

<p>Ohms (A)</p> Signup and view all the answers

What is the purpose of electroplating?

<p>To improve the appearance, durability, and resistance to corrosion of an object (C)</p> Signup and view all the answers

What is the characteristic of electric current in a series circuit?

<p>Current is the same at all points in the circuit (B)</p> Signup and view all the answers

What happens when more resistors are added in series?

<p>Total resistance of the circuit increases (C)</p> Signup and view all the answers

What is the unit of measurement for electric current?

<p>Ampere (C)</p> Signup and view all the answers

What is the purpose of an ammeter?

<p>To measure the electric current in a circuit (D)</p> Signup and view all the answers

What happens when more cells are connected in series?

<p>Total voltage increases (C)</p> Signup and view all the answers

What is the characteristic of a parallel circuit?

<p>There are multiple pathways for the electric current to follow (D)</p> Signup and view all the answers

What is the result of closing a circuit?

<p>Electrons start moving simultaneously (B)</p> Signup and view all the answers

What is the symbol for an ammeter in a circuit diagram?

<p>A circle with the letter 'A' inside it (A)</p> Signup and view all the answers

Why does an ammeter have low resistance?

<p>To not significantly affect the current flowing through the circuit (D)</p> Signup and view all the answers

What is common about the voltage across each component in a parallel circuit?

<p>It is the same (B)</p> Signup and view all the answers

What happens to the total resistance of a circuit when more resistors are added in parallel?

<p>It decreases (D)</p> Signup and view all the answers

What is the total current supplied by the battery in a parallel circuit?

<p>The sum of the currents through each branch (C)</p> Signup and view all the answers

What is a characteristic of LEDs?

<p>They do not have a filament and are energy efficient (C)</p> Signup and view all the answers

What is an application of LEDs?

<p>Used in various electronic applications such as electronic timepieces, televisions, and home lighting (D)</p> Signup and view all the answers

What is the result of adding more cells in parallel?

<p>The overall voltage of the circuit remains the same (C)</p> Signup and view all the answers

What is true about the current in parallel branches if they have identical components?

<p>The current will divide equally among the branches (C)</p> Signup and view all the answers

What is the energy conversion process in LEDs?

<p>Electrical energy is converted directly into light energy (C)</p> Signup and view all the answers

What is the primary benefit of LEDs over other light sources?

<p>They provide more light per unit of electricity consumed. (C)</p> Signup and view all the answers

What is a difference between LEDs and incandescent light bulbs?

<p>LEDs produce very little heat and consume less electricity than incandescent light bulbs (D)</p> Signup and view all the answers

What is an example of a luminous object?

<p>The Sun (B)</p> Signup and view all the answers

Why are LEDs more efficient than incandescent light bulbs?

<p>They convert a significant portion of electrical energy into light energy (D)</p> Signup and view all the answers

What is the term for the transfer of energy through space as electromagnetic waves?

<p>Radiation (A)</p> Signup and view all the answers

How does light travel through space?

<p>In straight lines (A)</p> Signup and view all the answers

What is the purpose of the pinhole camera activity?

<p>To understand how light travels (C)</p> Signup and view all the answers

What is the range of wavelengths of light that are visible to the human eye?

<p>Visible spectrum (A)</p> Signup and view all the answers

What is the color with the longest wavelength and lowest frequency in the visible spectrum?

<p>Red (A)</p> Signup and view all the answers

What happens when the colors of the visible spectrum are combined?

<p>They form white light (A)</p> Signup and view all the answers

What is the term for the process of separating a wave, such as light, into its constituent parts?

<p>Dispersion (C)</p> Signup and view all the answers

What is the speed at which light travels?

<p>300,000 kilometers per second (C)</p> Signup and view all the answers

What is the purpose of a sundial?

<p>To tell time (A)</p> Signup and view all the answers

What happens when light hits an opaque object?

<p>It casts a shadow (D)</p> Signup and view all the answers

What is the purpose of a filter?

<p>To allow specific colors of light to pass through (B)</p> Signup and view all the answers

What is absorption of light?

<p>The process by which a material takes in light energy (A)</p> Signup and view all the answers

Why do black surfaces become hotter than white surfaces when exposed to sunlight?

<p>Because they absorb more light energy (A)</p> Signup and view all the answers

What happens to light when it hits a mirror?

<p>It is reflected (B)</p> Signup and view all the answers

Why do ladybirds' black spots appear black?

<p>Because they absorb all colors of light (C)</p> Signup and view all the answers

What is the purpose of a red filter?

<p>To allow only red light to pass through (D)</p> Signup and view all the answers

Why do white objects appear white?

<p>Because they reflect all colors of light (B)</p> Signup and view all the answers

What happens when light hits a translucent object?

<p>It passes through partially (A)</p> Signup and view all the answers

What is the function of rods in the eye?

<p>To detect light and dark changes (D)</p> Signup and view all the answers

What happens to light when it enters a different medium at an angle?

<p>It changes direction (B)</p> Signup and view all the answers

What is the purpose of the optic nerve?

<p>To transmit electrical impulses to the brain (B)</p> Signup and view all the answers

What is the term for the bending of light as it passes from one medium to another?

<p>Refraction (C)</p> Signup and view all the answers

What determines how much a medium slows down light?

<p>Optical density (C)</p> Signup and view all the answers

What is the result of light traveling from a less dense medium to a denser medium?

<p>It slows down (D)</p> Signup and view all the answers

What is the purpose of cone cells in the retina?

<p>To detect color (D)</p> Signup and view all the answers

What happens to white light when it passes through a prism?

<p>It is refracted and split into its component colors (D)</p> Signup and view all the answers

What is the purpose of the lens in the eye?

<p>To focus light onto the retina (D)</p> Signup and view all the answers

What is the result of placing a straw in a glass of water?

<p>It appears to be bent (A)</p> Signup and view all the answers

What happens when you rub a balloon on your hair?

<p>Electrons transfer from your hair to the balloon, making your hair positively charged and the balloon negatively charged. (B)</p> Signup and view all the answers

What is the purpose of earthing?

<p>To safely discharge extra electrons from an object into the Earth. (C)</p> Signup and view all the answers

What is an electric current?

<p>The movement of electric charge through a closed, conducting circuit. (C)</p> Signup and view all the answers

What is the role of a conductor in an electric circuit?

<p>To allow the flow of electric current. (B)</p> Signup and view all the answers

What is the function of a switch in an electric circuit?

<p>To control the flow of electric current. (B)</p> Signup and view all the answers

What is the purpose of a resistor in an electric circuit?

<p>To convert electrical energy into heat. (A)</p> Signup and view all the answers

What is the difference between a conductor and an insulator?

<p>Conductors allow the flow of electric current, while insulators do not. (A)</p> Signup and view all the answers

What is the purpose of a Van de Graaff generator?

<p>To generate a large electric charge on a metal dome. (D)</p> Signup and view all the answers

What is the purpose of an electroscope?

<p>To detect the presence and type of charge on an object. (C)</p> Signup and view all the answers

What is a necessary component of an electric circuit?

<p>A source of energy. (B)</p> Signup and view all the answers

What symbol is used to represent a battery in a circuit diagram?

<p>Multiple sets of parallel lines (B)</p> Signup and view all the answers

What is the function of a fuse in an electrical circuit?

<p>To protect the circuit from overheating (B)</p> Signup and view all the answers

What happens when an electric current flows through a resistor?

<p>It converts electrical energy into heat (C)</p> Signup and view all the answers

What is the purpose of a circuit breaker in a modern home?

<p>To protect the circuit from damage by stopping the current flow during overloads or short circuits (B)</p> Signup and view all the answers

What is the principle behind the operation of electromagnets?

<p>The magnetic effect of electric current (B)</p> Signup and view all the answers

What is the result of electrolysis of copper chloride solution?

<p>The separation of copper and chlorine (C)</p> Signup and view all the answers

What is the function of the filament in a light bulb?

<p>To convert electrical energy into heat (A)</p> Signup and view all the answers

What is the purpose of the heating element in a kettle?

<p>To convert electrical energy into heat (C)</p> Signup and view all the answers

What is represented by a circle with a cross inside in a circuit diagram?

<p>A light bulb (A)</p> Signup and view all the answers

What is the effect of electric current on a solution during electrolysis?

<p>It breaks down the solution into its component elements (D)</p> Signup and view all the answers

What occurs when light passes through a prism?

<p>Light is split into its constituent colors (C)</p> Signup and view all the answers

What is the longest wavelength of visible light?

<p>700 nanometers (A)</p> Signup and view all the answers

What type of light is used in forensics and to sterilize medical equipment?

<p>Ultraviolet light (B)</p> Signup and view all the answers

What is the term for substances that do not transmit light?

<p>Opaque (C)</p> Signup and view all the answers

What happens to light when it hits an opaque surface?

<p>It is reflected by the surface (A)</p> Signup and view all the answers

What is the frequency of a wave?

<p>The number of waves that pass a point in one second (D)</p> Signup and view all the answers

What is the purpose of a prism in an experiment?

<p>To split light into its constituent colors (A)</p> Signup and view all the answers

What type of light is felt as heat?

<p>Infrared light (D)</p> Signup and view all the answers

What is the term for substances that transmit some light but not enough to see through clearly?

<p>Translucent (D)</p> Signup and view all the answers

What is the result of light passing through a transparent substance?

<p>The light passes through the substance with little absorption or reflection (B)</p> Signup and view all the answers

What occurs when light enters a raindrop?

<p>It is refracted and dispersed (B)</p> Signup and view all the answers

What is the purpose of a converging lens?

<p>To focus light rays to a point (B)</p> Signup and view all the answers

What type of lens is used to correct near-sightedness?

<p>Diverging lens (biconcave) (D)</p> Signup and view all the answers

What happens to light as it exits a raindrop?

<p>It is refracted again (A)</p> Signup and view all the answers

What is the purpose of the normal line in understanding reflection?

<p>To draw an imaginary line perpendicular to the surface at the point of incidence (A)</p> Signup and view all the answers

What is an application of lenses?

<p>Correcting vision and magnifying images (D)</p> Signup and view all the answers

What is the law of reflection?

<p>The angle of incidence is equal to the angle of reflection (C)</p> Signup and view all the answers

What is the result of refraction and dispersion in a raindrop?

<p>A rainbow (D)</p> Signup and view all the answers

What is the function of the cornea in the eye?

<p>To focus light (B)</p> Signup and view all the answers

What is the process of light entering the eye?

<p>Light entry (A)</p> Signup and view all the answers

What is the function of photoreceptor cells in the retina?

<p>To detect light (B)</p> Signup and view all the answers

What is the result of light reflecting off a smooth surface?

<p>A clear and focused image (D)</p> Signup and view all the answers

What is the function of the iris in the eye?

<p>To change the pupil's size (B)</p> Signup and view all the answers

What is the angle between the incident ray and the normal line?

<p>Angle of incidence (B)</p> Signup and view all the answers

What is the result of light reflecting off a rough surface?

<p>A diffuse and unclear reflection (A)</p> Signup and view all the answers

What is the purpose of the lens in the eye?

<p>To focus light (D)</p> Signup and view all the answers

When a comb is dragged through hair, what happens to the electrons?

<p>They move from the hair to the comb (D)</p> Signup and view all the answers

What is the result of an object gaining more electrons than protons?

<p>The object becomes negatively charged (A)</p> Signup and view all the answers

Why do objects with the same charge repel each other?

<p>Because they have the same type of charge (D)</p> Signup and view all the answers

What is the term for the resistance against the movement of an object resulting from its contact with another object?

<p>Friction (B)</p> Signup and view all the answers

What happens when two objects with opposite charges interact?

<p>They attract each other (D)</p> Signup and view all the answers

What is the normal state of an atom?

<p>Neutral (C)</p> Signup and view all the answers

What is the result of combing your hair with a plastic comb?

<p>Your hair becomes negatively charged (B)</p> Signup and view all the answers

What is the purpose of friction in the context of static electricity?

<p>To transfer electrons (C)</p> Signup and view all the answers

What happens when there is a significant build-up of charge on an object?

<p>A spark is produced through contact or across an air gap. (A)</p> Signup and view all the answers

What is the purpose of earthing an object?

<p>To safely discharge extra electrons from the object. (C)</p> Signup and view all the answers

What is an electric current?

<p>The movement of electric charge through a closed, conducting circuit. (A)</p> Signup and view all the answers

What is the function of a conductor in a circuit?

<p>To allow the flow of electric current. (A)</p> Signup and view all the answers

What is the purpose of a switch in a circuit?

<p>To control the flow of current in the circuit. (B)</p> Signup and view all the answers

What is the purpose of a load in a circuit?

<p>To use the electrical energy. (D)</p> Signup and view all the answers

What is a characteristic of metals?

<p>Electrons are free to move and are not bound to any specific atom. (A)</p> Signup and view all the answers

What is the function of an electroscope?

<p>To detect the presence and type of charge on an object. (D)</p> Signup and view all the answers

What is a Van de Graaff generator used for?

<p>To generate a large electric charge on a metal dome. (D)</p> Signup and view all the answers

What is required for an electric current to flow?

<p>A closed, conducting circuit. (A)</p> Signup and view all the answers

What is the main purpose of electroplating?

<p>To improve the appearance and durability of a metal object (D)</p> Signup and view all the answers

In a series circuit, what happens to the total resistance when more resistors are added?

<p>It increases (A)</p> Signup and view all the answers

What is the function of an ammeter in a circuit?

<p>To measure the current of a circuit (C)</p> Signup and view all the answers

In a parallel circuit, what is true about the voltage across each component?

<p>It is the same for each component (D)</p> Signup and view all the answers

What happens to the current in a series circuit when more resistors are added?

<p>It decreases (C)</p> Signup and view all the answers

What is the characteristic of electric current in a series circuit?

<p>It has a single pathway (C)</p> Signup and view all the answers

What is the purpose of connecting cells in series?

<p>To increase the total voltage (A)</p> Signup and view all the answers

Why does an ammeter have low resistance?

<p>So it can measure current accurately (B)</p> Signup and view all the answers

What is the main difference between a series circuit and a parallel circuit?

<p>The pathway of the electric current in the circuit (D)</p> Signup and view all the answers

What happens when a component fails in a series circuit?

<p>The entire circuit is affected (D)</p> Signup and view all the answers

What is the primary benefit of LEDs over other light sources?

<p>They provide more light per unit of electricity consumed and generate less heat (C)</p> Signup and view all the answers

What is the term for objects that emit light?

<p>Luminous (C)</p> Signup and view all the answers

How does light travel through space?

<p>In straight lines (D)</p> Signup and view all the answers

What is the range of wavelengths of light that are visible to the human eye?

<p>Visible spectrum (C)</p> Signup and view all the answers

What is the color with the longest wavelength and lowest frequency in the visible spectrum?

<p>Red (B)</p> Signup and view all the answers

What happens when the colors of the visible spectrum are combined?

<p>They form white light (C)</p> Signup and view all the answers

What is the term for the process of separating a wave, such as light, into its constituent parts?

<p>Dispersion (C)</p> Signup and view all the answers

What is the speed at which light travels?

<p>300,000 kilometers per second (C)</p> Signup and view all the answers

What is the purpose of the pinhole camera activity?

<p>To understand how light travels in straight lines (C)</p> Signup and view all the answers

What is an example of a luminous object?

<p>All of the above (D)</p> Signup and view all the answers

What is the function of the cornea in the human eye?

<p>To focus light onto the retina (B)</p> Signup and view all the answers

What is the law of reflection?

<p>The angle of incidence is equal to the angle of reflection (A)</p> Signup and view all the answers

What is the purpose of the normal line in understanding reflection?

<p>To draw an imaginary line perpendicular to the surface at the point of incidence (A)</p> Signup and view all the answers

What is the term for the light-sensitive cells in the retina?

<p>Photoreceptor cells (C)</p> Signup and view all the answers

What is the function of the pupil in the human eye?

<p>To open and close to regulate light entry (A)</p> Signup and view all the answers

What is the characteristic of a smooth surface in terms of reflection?

<p>It reflects light uniformly, creating a clear image (A)</p> Signup and view all the answers

What is the purpose of the retina in the human eye?

<p>To convert light into electrical signals (C)</p> Signup and view all the answers

What is the angle of incidence?

<p>The angle between the incident ray and the normal line (A)</p> Signup and view all the answers

What is the result of reflection off a rough surface?

<p>A diffuse and unclear reflection (B)</p> Signup and view all the answers

What is the term for the process of light entering the eye?

<p>Refraction (D)</p> Signup and view all the answers

What occurs when light enters a raindrop, creating a rainbow?

<p>Dispersion and reflection (A)</p> Signup and view all the answers

What is the purpose of a converging lens?

<p>To focus light rays to a point (B)</p> Signup and view all the answers

What is used to correct near-sightedness?

<p>Diverging lenses (A)</p> Signup and view all the answers

What is the main application of lenses?

<p>To correct vision and magnify images (B)</p> Signup and view all the answers

What type of lens is used to correct far-sightedness?

<p>Converging lens (D)</p> Signup and view all the answers

What is the process by which light is separated into its constituent parts?

<p>Dispersion (C)</p> Signup and view all the answers

What is the primary function of a switch in a circuit?

<p>To control the flow of current (D)</p> Signup and view all the answers

What happens when a circuit is broken?

<p>The current stops flowing through the circuit (A)</p> Signup and view all the answers

What is the purpose of building a simple circuit?

<p>To demonstrate the concept of open and closed circuits (B)</p> Signup and view all the answers

What is the difference between a cell and a battery?

<p>A battery is a group of cells connected together (A)</p> Signup and view all the answers

What is the purpose of a resistor in a circuit?

<p>To convert electrical energy into heat energy (B)</p> Signup and view all the answers

What is the characteristic of a series circuit?

<p>A single path for the current to flow (B)</p> Signup and view all the answers

What happens when a component fails in a parallel circuit?

<p>The current flows through the other paths (D)</p> Signup and view all the answers

What is the purpose of wires in a circuit?

<p>To conduct the current between components (B)</p> Signup and view all the answers

What is the result of closing a circuit?

<p>The light bulb lights up (D)</p> Signup and view all the answers

What is the primary benefit of understanding electric circuits?

<p>To explore more complex electrical systems and practical applications (A)</p> Signup and view all the answers

What is the main characteristic of a parallel circuit?

<p>Components are connected across common points or junctions, creating multiple paths for the current. (A)</p> Signup and view all the answers

What happens to the total resistance of a circuit when more resistors are added in parallel?

<p>The total resistance decreases. (A)</p> Signup and view all the answers

What is the relationship between the total current and branch currents in a parallel circuit?

<p>A1 = A2 + A3 (D)</p> Signup and view all the answers

What is a characteristic of LEDs?

<p>They emit light through electroluminescence. (B)</p> Signup and view all the answers

What happens to the current in parallel branches if they have identical components?

<p>The current will divide equally among the branches. (A)</p> Signup and view all the answers

What is the purpose of a light bulb in a circuit?

<p>To convert electrical energy into light energy. (B)</p> Signup and view all the answers

What is the result of adding more cells in parallel?

<p>The total current of the circuit remains the same. (A)</p> Signup and view all the answers

What is the energy conversion process in LEDs?

<p>Electrical energy → Light energy (B)</p> Signup and view all the answers

What is the primary benefit of LEDs over other light sources?

<p>They consume less electricity. (A)</p> Signup and view all the answers

What is a difference between LEDs and incandescent light bulbs?

<p>Incandescent bulbs have a filament, while LEDs do not. (B)</p> Signup and view all the answers

What is the primary reason why we see a rainbow when light passes through raindrops in the atmosphere?

<p>Different wavelengths of light bend by different amounts (B)</p> Signup and view all the answers

What is the term for the distance between two corresponding points on consecutive waves of light?

<p>Wavelength (A)</p> Signup and view all the answers

What type of electromagnetic wave has a shorter wavelength and higher frequency than visible light?

<p>Ultraviolet (UV) Light (C)</p> Signup and view all the answers

What is the term for substances that do not transmit light, and instead reflect or absorb it?

<p>Opaque (D)</p> Signup and view all the answers

What happens when light hits a transparent substance?

<p>It passes through the substance with little absorption or reflection (B)</p> Signup and view all the answers

What is an example of a translucent substance?

<p>Cellophane (D)</p> Signup and view all the answers

What is the term for the process of separating a wave, such as light, into its constituent parts?

<p>Dispersion (C)</p> Signup and view all the answers

What is the range of wavelengths of light that are visible to the human eye?

<p>400-700 nanometers (D)</p> Signup and view all the answers

What is the color with the shortest wavelength and highest frequency in the visible spectrum?

<p>Violet (A)</p> Signup and view all the answers

What is the result of combining the colors of the visible spectrum?

<p>White light (A)</p> Signup and view all the answers

What is the function of a fuse in an electrical circuit?

<p>To protect electrical circuits from overheating (D)</p> Signup and view all the answers

What is the symbol for a resistor in a circuit diagram?

<p>A zigzag line (A)</p> Signup and view all the answers

What is the purpose of a variable resistor in a circuit?

<p>To increase or decrease the current in a circuit (B)</p> Signup and view all the answers

What happens when an electric current flows through a resistor?

<p>The resistor converts electrical energy into heat (D)</p> Signup and view all the answers

What is the term for the process of passing an electric current through a liquid or solution to break it down into its component elements?

<p>Electrolysis (C)</p> Signup and view all the answers

What is the purpose of a circuit breaker in an electrical circuit?

<p>To protect electrical circuits from damage by stopping the current flow during overloads or short circuits (B)</p> Signup and view all the answers

What is the effect of an electric current on the filament in a light bulb?

<p>It causes the filament to heat up and emit light (A)</p> Signup and view all the answers

What is the function of an electromagnet in a device such as an electric bell?

<p>To create a magnetic field that vibrates a diaphragm to produce sound (A)</p> Signup and view all the answers

What is the result of the heating effect of an electric current?

<p>The conversion of electrical energy into heat (C)</p> Signup and view all the answers

What is the purpose of a switch in an electrical circuit?

<p>To control the flow of current in a circuit (A)</p> Signup and view all the answers

What is the primary purpose of using a transparent object as a filter?

<p>To allow specific colors of light to pass through (D)</p> Signup and view all the answers

What happens when light hits an object with a transparent surface?

<p>The light passes through the object (D)</p> Signup and view all the answers

What is the main difference between a black object and a white object?

<p>Black objects absorb all colors of light, while white objects reflect all colors of light (C)</p> Signup and view all the answers

Why do black clothes make you feel hotter on a sunny day?

<p>Because black clothes absorb more light and convert it into heat (A)</p> Signup and view all the answers

What is the purpose of using a red filter in photography?

<p>To absorb all colors of light except red (A)</p> Signup and view all the answers

What is the result of an object absorbing all colors of light?

<p>The object appears black (D)</p> Signup and view all the answers

What is the principle behind the use of shadows to tell time with a sundial?

<p>The shadow of the sundial's gnomon moves across its marked surface as the Sun moves across the sky (C)</p> Signup and view all the answers

What is the function of a mirror?

<p>To reflect light with minimal absorption (C)</p> Signup and view all the answers

Why are solar panels usually black?

<p>Because black surfaces absorb the maximum amount of light (B)</p> Signup and view all the answers

What is the result of light hitting a translucent substance?

<p>The light passes through the substance, but is scattered (C)</p> Signup and view all the answers

What type of photoreceptor cells are sensitive to shape, movement, and light and dark changes?

<p>Rod cells (B)</p> Signup and view all the answers

What happens to light when it travels from one medium to another?

<p>It changes direction (C)</p> Signup and view all the answers

What is the purpose of the lens in the eye?

<p>To focus light onto the retina (D)</p> Signup and view all the answers

What is the name of the process by which light is separated into its component colors?

<p>Dispersion (B)</p> Signup and view all the answers

What determines how much a medium slows down light?

<p>Optical density (C)</p> Signup and view all the answers

What appears to happen to a straw in a glass of water?

<p>It appears bent (A)</p> Signup and view all the answers

What is the function of the optic nerve?

<p>To transmit signals to the brain (B)</p> Signup and view all the answers

What is the term for the bending of light as it passes from one medium to another?

<p>Refraction (B)</p> Signup and view all the answers

What determines the color of an object?

<p>The wavelength of light it reflects (C)</p> Signup and view all the answers

What happens to light when it enters a different medium at an angle?

<p>It changes direction (D)</p> Signup and view all the answers

What occurs when an object gains electrons due to friction?

<p>The object becomes negatively charged. (C)</p> Signup and view all the answers

What is the result of two objects with the same charge interacting?

<p>They repel each other. (C)</p> Signup and view all the answers

What causes an atom to be neutral?

<p>An equal number of protons and electrons. (B)</p> Signup and view all the answers

What is the purpose of friction in the context of static electricity?

<p>To transfer electrons between objects. (D)</p> Signup and view all the answers

What is the term for the forces that hold the nucleus of an atom together?

<p>Strong forces. (A)</p> Signup and view all the answers

What is the net result of combing your hair with a plastic comb?

<p>Electrons are transferred from the hair to the comb. (B)</p> Signup and view all the answers

What is the characteristic of an object that has more protons than electrons?

<p>It is positively charged. (C)</p> Signup and view all the answers

What is the reason behind the attraction between two objects with opposite charges?

<p>Opposite charges attract each other. (A)</p> Signup and view all the answers

What is the primary function of a fuse in an electrical circuit?

<p>To protect the circuit from overheating (C)</p> Signup and view all the answers

What is the effect of electric current on a resistor?

<p>It converts electrical energy into heat (D)</p> Signup and view all the answers

What is the purpose of electrolysis in electroplating?

<p>To purify metals (D)</p> Signup and view all the answers

What is the effect of an electric current on a light bulb?

<p>It converts electrical energy into light (B)</p> Signup and view all the answers

What is the purpose of a circuit breaker in an electrical circuit?

<p>To protect the circuit from overheating (A)</p> Signup and view all the answers

What is the effect of electric current on a kettle?

<p>It converts electrical energy into heat (B)</p> Signup and view all the answers

What is the purpose of a resistor in a circuit diagram?

<p>To represent a resistor or resistance in the circuit (D)</p> Signup and view all the answers

What is the effect of electric current on a magnet?

<p>It creates a magnetic field around the magnet (B)</p> Signup and view all the answers

What is the purpose of a variable resistor in a circuit?

<p>To vary the resistance in the circuit (C)</p> Signup and view all the answers

What is the effect of electric current on a solution?

<p>It causes a chemical reaction in the solution (A)</p> Signup and view all the answers

What is the primary reason why shadows are created?

<p>Because light cannot pass through opaque objects (A)</p> Signup and view all the answers

What is the purpose of using a red filter in photography?

<p>To transmit only red light and absorb other colors (C)</p> Signup and view all the answers

What happens to light energy when it hits a black object?

<p>It is absorbed and converted into heat (A)</p> Signup and view all the answers

What is the reason why solar panels are usually black?

<p>Because black surfaces absorb the maximum amount of light (A)</p> Signup and view all the answers

What is the difference between a blackboard and a whiteboard?

<p>A blackboard absorbs most of the light, while a whiteboard reflects most of the light (C)</p> Signup and view all the answers

What is the characteristic of light that allows us to see objects and create mirror images?

<p>Reflection (C)</p> Signup and view all the answers

What is the reason why wearing black clothes on a sunny day can make you feel hotter?

<p>Because black clothes absorb most of the sunlight (D)</p> Signup and view all the answers

What is the term for the process by which a material takes in light energy?

<p>Absorption (D)</p> Signup and view all the answers

What is the characteristic of light that allows it to travel through space?

<p>Traveling in straight lines (A)</p> Signup and view all the answers

What is the purpose of using a sundial?

<p>To tell time (B)</p> Signup and view all the answers

What is the primary function of the normal line in the context of reflection?

<p>To draw a perpendicular line to the surface at the point of incidence (B)</p> Signup and view all the answers

What type of surface would produce a diffuse reflection?

<p>Rough surface (C)</p> Signup and view all the answers

What is the term for the bending of light as it passes from one medium to another?

<p>Refraction (B)</p> Signup and view all the answers

What is the primary function of the lens in the eye?

<p>To focus light (C)</p> Signup and view all the answers

What is the term for the light-sensitive cells in the retina?

<p>Photoreceptors (B)</p> Signup and view all the answers

What is the result of the law of reflection?

<p>The angle of incidence is equal to the angle of reflection (A)</p> Signup and view all the answers

What is the primary function of the cornea?

<p>To focus light (D)</p> Signup and view all the answers

What is the purpose of the pupil?

<p>To regulate the amount of light that enters the eye (A)</p> Signup and view all the answers

What is the term for the process of light entering the eye?

<p>Light entry (D)</p> Signup and view all the answers

What is the primary function of the retina?

<p>To convert light into electrical signals (A)</p> Signup and view all the answers

What occurs when light enters a raindrop?

<p>It refracts and is split into its component colors. (B)</p> Signup and view all the answers

What is the purpose of a converging lens?

<p>To bend light rays inward to a focal point. (C)</p> Signup and view all the answers

What type of lens is used to correct near-sightedness?

<p>Diverging lens (biconcave) (D)</p> Signup and view all the answers

What happens to light as it exits a raindrop?

<p>It refracts and is split into its component colors. (A)</p> Signup and view all the answers

What is the main application of lenses?

<p>To correct vision and magnify images. (D)</p> Signup and view all the answers

What is the result of the refraction and reflection of light in a raindrop?

<p>A rainbow with its component colors. (C)</p> Signup and view all the answers

What is the primary function of a closed circuit?

<p>To enable the flow of electric current. (D)</p> Signup and view all the answers

What is the effect on a parallel circuit if one component fails?

<p>The current can still flow through the other paths. (B)</p> Signup and view all the answers

What is the purpose of a switch in a circuit?

<p>To control the flow of current. (A)</p> Signup and view all the answers

What is the advantage of using a variable resistor?

<p>It enables the dynamic control of current flow. (A)</p> Signup and view all the answers

What is the function of wires in a circuit?

<p>To conduct the current between the components. (B)</p> Signup and view all the answers

What is true about the flow of current in a series circuit?

<p>It is affected by the resistance of each component. (A)</p> Signup and view all the answers

What is the effect of connecting more cells in series?

<p>The total voltage increases. (B)</p> Signup and view all the answers

What is true about the current in a parallel circuit?

<p>It is not affected by the failure of one component. (B)</p> Signup and view all the answers

What is the purpose of a resistor in a circuit?

<p>To oppose the flow of electric current. (C)</p> Signup and view all the answers

What is the effect of adding more resistors in parallel?

<p>The total resistance decreases. (B)</p> Signup and view all the answers

In a parallel circuit, what is the relationship between the total current and the current through each branch?

<p>The total current is the sum of the currents through each branch. (D)</p> Signup and view all the answers

What is the primary benefit of using LEDs over incandescent light bulbs?

<p>LEDs are more efficient and produce less heat. (A)</p> Signup and view all the answers

What is the primary reason for electroplating a metal object?

<p>To improve the object's appearance, durability, and resistance to corrosion (A)</p> Signup and view all the answers

What happens to the total resistance of a circuit when more resistors are added in parallel?

<p>The total resistance decreases. (C)</p> Signup and view all the answers

What is the key difference between a series circuit and a parallel circuit?

<p>The pathway of electric current in the circuit (D)</p> Signup and view all the answers

What is the characteristic of electric current in a parallel circuit?

<p>The current through each branch is the same. (D)</p> Signup and view all the answers

What is the term for the process of converting electrical energy directly into light energy in LEDs?

<p>Electroluminescence. (A)</p> Signup and view all the answers

What happens to the total resistance of a series circuit when more resistors are added?

<p>It increases (B)</p> Signup and view all the answers

What is the purpose of an ammeter in a circuit?

<p>To measure the electric current in the circuit (D)</p> Signup and view all the answers

What happens to the current strength when more cells are added in parallel?

<p>The current strength remains the same. (D)</p> Signup and view all the answers

What is the result of adding more resistors in parallel to a circuit?

<p>The total current increases. (B)</p> Signup and view all the answers

What happens to the electric current in a series circuit when more cells are added?

<p>It increases, provided the total resistance remains constant (B)</p> Signup and view all the answers

What is the characteristic of the voltage across each component in a parallel circuit?

<p>The voltage across each component is the same. (D)</p> Signup and view all the answers

What is a characteristic of electron movement in a conductor?

<p>Electrons move freely within the metal (C)</p> Signup and view all the answers

What is the symbol for an ammeter in a circuit diagram?

<p>A circle with the letter 'A' inside (C)</p> Signup and view all the answers

What is the benefit of using parallel circuits over series circuits?

<p>Parallel circuits are less prone to component failure. (C)</p> Signup and view all the answers

Why does an ammeter have low resistance?

<p>So that it does not significantly affect the current flowing through the circuit (D)</p> Signup and view all the answers

What is the purpose of using multiple exits in a school hall?

<p>To allow students to exit more quickly and efficiently. (B)</p> Signup and view all the answers

What is a characteristic of a parallel circuit?

<p>There is more than one pathway for electric current (C)</p> Signup and view all the answers

What happens when a component fails in a series circuit?

<p>The circuit is broken and the current stops flowing (C)</p> Signup and view all the answers

What is the primary reason for the separation of colors when light passes through a prism?

<p>Due to the difference in the wavelengths of the colors (B)</p> Signup and view all the answers

What is the primary reason why LEDs are preferred in many applications?

<p>They provide more light per unit of electricity consumed and generate less heat (B)</p> Signup and view all the answers

What type of waves are used in forensics and to sterilize medical equipment?

<p>Ultraviolet (UV) light (B)</p> Signup and view all the answers

What happens to light when it hits a translucent substance?

<p>It is scattered in different directions (C)</p> Signup and view all the answers

What is the term for objects that emit light?

<p>Luminous (C)</p> Signup and view all the answers

What is the process of separating a wave, such as light, into its constituent parts?

<p>Dispersion (A)</p> Signup and view all the answers

What is the shortest wavelength and highest frequency light in the visible spectrum?

<p>Violet light (D)</p> Signup and view all the answers

What is the purpose of the activity involving a prism and a light source?

<p>To investigate the visible spectrum (D)</p> Signup and view all the answers

What is the color with the shortest wavelength and highest frequency in the visible spectrum?

<p>Violet (C)</p> Signup and view all the answers

What is the term for the distance between two corresponding points on consecutive waves?

<p>Wavelength (B)</p> Signup and view all the answers

What is the approximate time it takes for light to travel from the Sun to the Earth?

<p>8 minutes (C)</p> Signup and view all the answers

What is the purpose of lining the inside of the pinhole camera box with black paper?

<p>To minimize reflections (C)</p> Signup and view all the answers

What type of electromagnetic waves are used for cooking and satellite transmissions?

<p>Microwaves (C)</p> Signup and view all the answers

What is the characteristic of light when it passes through a transparent substance?

<p>It passes through with little absorption or reflection (C)</p> Signup and view all the answers

What is the result of combining the colors of the visible spectrum?

<p>White light (C)</p> Signup and view all the answers

What is the term for the movement of light through space?

<p>Propagation (C)</p> Signup and view all the answers

What is the process of separating a wave, such as light, into its constituent parts?

<p>Dispersion (B)</p> Signup and view all the answers

What is the speed at which light travels?

<p>300,000 kilometers per second (D)</p> Signup and view all the answers

What happens when light hits an opaque substance?

<p>It is absorbed or reflected (B)</p> Signup and view all the answers

What is the term for objects that do not emit their own light?

<p>Non-Luminous (D)</p> Signup and view all the answers

What is the primary reason for the buildup of charge on an object through friction?

<p>The transfer of electrons from one object to another (D)</p> Signup and view all the answers

What is the purpose of earthing an object?

<p>To safely discharge excess electrons from the object (D)</p> Signup and view all the answers

What is the function of a Van de Graaff generator?

<p>To generate a large electric charge on a metal dome (D)</p> Signup and view all the answers

What is the characteristic of electric current in a metal?

<p>The flow of electric charge is carried by delocalized electrons (B)</p> Signup and view all the answers

What is the purpose of a conductor in an electric circuit?

<p>To allow the flow of electric current through the circuit (A)</p> Signup and view all the answers

What is the result of connecting a load to a circuit?

<p>The circuit becomes closed and current can flow (B)</p> Signup and view all the answers

What is the primary function of a switch in an electric circuit?

<p>To control the flow of current through the circuit (D)</p> Signup and view all the answers

What is the difference between a conductor and an insulator?

<p>A conductor allows the flow of electric current, while an insulator does not (D)</p> Signup and view all the answers

What is the purpose of a simple circuit diagram?

<p>To visualize the components and their connections in the circuit (D)</p> Signup and view all the answers

What is the result of combing your hair with a plastic comb?

<p>Your hair becomes positively charged (C)</p> Signup and view all the answers

What is the main function of rods in the human eye?

<p>To detect light and dark changes, shapes, and movement (C)</p> Signup and view all the answers

Which structure in the eye controls the amount of light that enters?

<p>Iris (A)</p> Signup and view all the answers

What is the process by which light bends as it passes from one medium to another?

<p>Refraction (B)</p> Signup and view all the answers

Why does light refract when it passes from one medium to another?

<p>Because of the change in speed (B)</p> Signup and view all the answers

What is the term for a measure of how much a medium can slow down light?

<p>Optical density (A)</p> Signup and view all the answers

What is the result of refraction in a prism?

<p>Dispersion of light (D)</p> Signup and view all the answers

What is the purpose of the optic nerve in the process of vision?

<p>To transmit electrical signals from the eye to the brain (D)</p> Signup and view all the answers

What is the function of cone cells in the retina?

<p>To detect different wavelengths of light (B)</p> Signup and view all the answers

What is the result of placing a straw in a glass of water?

<p>The straw appears bent (B)</p> Signup and view all the answers

What is the term for the process of interpreting electrical signals as visual images?

<p>Brain interpretation (A)</p> Signup and view all the answers

What is the process that splits white light into its component colors, creating a rainbow?

<p>Dispersion (C)</p> Signup and view all the answers

What type of lens is used to correct near-sightedness?

<p>Diverging lens (A)</p> Signup and view all the answers

What is the function of a converging lens?

<p>To focus light rays to a single point (B)</p> Signup and view all the answers

What is the purpose of corrective lenses in glasses?

<p>To correct vision (D)</p> Signup and view all the answers

What occurs when light enters a raindrop?

<p>It is refracted (A)</p> Signup and view all the answers

What is the term for the bending of light as it passes from one medium to another?

<p>Refraction (C)</p> Signup and view all the answers

What is the result of light being refracted through a triangular prism?

<p>The light is dispersed into its component colors (C)</p> Signup and view all the answers

What is the term for the separation of light into its component colors?

<p>Dispersion (B)</p> Signup and view all the answers

What is the purpose of a converging lens in a microscope?

<p>To focus light rays (C)</p> Signup and view all the answers

What is the result of light being reflected off the back of a raindrop?

<p>The light is transmitted back out of the raindrop (D)</p> Signup and view all the answers

What is the process responsible for creating a rainbow?

<p>Refraction (A), Dispersion (D)</p> Signup and view all the answers

What is the function of a converging lens?

<p>To bend light rays inward (A)</p> Signup and view all the answers

What type of lens is used to correct near-sightedness?

<p>Diverging lens (B)</p> Signup and view all the answers

What is the result of light refraction as it enters a raindrop?

<p>It is split into its component colors (C)</p> Signup and view all the answers

What is the purpose of lenses in optical devices?

<p>All of the above (D)</p> Signup and view all the answers

What happens to light as it exits a raindrop?

<p>It is refracted again (D)</p> Signup and view all the answers

What type of lens is used to correct far-sightedness?

<p>Converging lens (D)</p> Signup and view all the answers

What is the result of dispersion in a rainbow?

<p>Component colors are separated (D)</p> Signup and view all the answers

What is the purpose of a diverging lens?

<p>To spread light rays apart (D)</p> Signup and view all the answers

What is the application of lenses in microscopes?

<p>To magnify images (B)</p> Signup and view all the answers

What is the primary reason why rainbows appear in the sky?

<p>Light from the Sun refracts as it enters a raindrop and reflects off the back of the drop (D)</p> Signup and view all the answers

What is the main function of a converging lens?

<p>To bend light rays inward to a focal point (B)</p> Signup and view all the answers

What type of lens is used to correct near-sightedness?

<p>Diverging lens (biconcave) (C)</p> Signup and view all the answers

What is the process by which white light is split into its component colors?

<p>Dispersion (D)</p> Signup and view all the answers

What is the shape of the lenses used to correct far-sightedness?

<p>Biconvex (A)</p> Signup and view all the answers

What is the purpose of lenses in optical devices such as glasses and microscopes?

<p>To correct vision and magnify images (C)</p> Signup and view all the answers

What happens to light when it enters a raindrop?

<p>It refracts and changes direction (A)</p> Signup and view all the answers

What is the result of the process of refraction and dispersion in a rainbow?

<p>A range of colors is produced with different wavelengths (D)</p> Signup and view all the answers

What is the main difference between a converging lens and a diverging lens?

<p>The direction of bending of light rays (C)</p> Signup and view all the answers

What is the purpose of a diverging lens?

<p>To disperse light rays outward (B)</p> Signup and view all the answers

What is the main reason why rainbows display a band of colors?

<p>Light is refracted and dispersed as it passes through the raindrop (A)</p> Signup and view all the answers

What is the purpose of a converging lens?

<p>To bend light rays inward to a focal point (A)</p> Signup and view all the answers

What type of lens is used to correct near-sightedness?

<p>Diverging lens (A)</p> Signup and view all the answers

What is the result of light refracting through a prism?

<p>Light is split into its component colors (B)</p> Signup and view all the answers

What is the purpose of a diverging lens?

<p>To spread light rays apart (C)</p> Signup and view all the answers

What is the application of lenses in corrective eyewear?

<p>To correct vision (D)</p> Signup and view all the answers

What is the result of light reflecting off the back of a raindrop?

<p>Light is reflected back (D)</p> Signup and view all the answers

What is the term for the bending of light as it passes from one medium to another?

<p>Refraction (D)</p> Signup and view all the answers

What is the purpose of a lens in a microscope?

<p>To magnify objects (B)</p> Signup and view all the answers

What is the result of light passing through a converging lens?

<p>Light is focused to a point (C)</p> Signup and view all the answers

What is the primary mechanism responsible for the formation of a rainbow?

<p>Refraction and dispersion (B)</p> Signup and view all the answers

What is the function of a converging lens?

<p>To focus light rays to a point (D)</p> Signup and view all the answers

What type of lens is used to correct near-sightedness?

<p>Diverging lens (D)</p> Signup and view all the answers

What is the result of light passing through a triangular prism?

<p>It is refracted and dispersed (D)</p> Signup and view all the answers

What is the purpose of lenses in optical devices such as microscopes and telescopes?

<p>To focus and magnify images (D)</p> Signup and view all the answers

What is the term for the process of bending light rays?

<p>Refraction (B)</p> Signup and view all the answers

What is the result of light reflecting off the back of a raindrop?

<p>It is refracted again (B)</p> Signup and view all the answers

What type of lens is used to correct far-sightedness?

<p>Converging lens (A)</p> Signup and view all the answers

What is the purpose of glasses?

<p>To correct vision (A)</p> Signup and view all the answers

What is the result of light passing through a raindrop?

<p>It is refracted and dispersed (C)</p> Signup and view all the answers

What is responsible for creating a rainbow?

<p>All of the above (D)</p> Signup and view all the answers

What type of lens is used to correct near-sightedness?

<p>Diverging lens (biconcave) (C)</p> Signup and view all the answers

What is the primary function of lenses in optical devices?

<p>To focus or disperse light (D)</p> Signup and view all the answers

What happens to light as it enters a raindrop?

<p>It refracts and splits into its component colors (B)</p> Signup and view all the answers

What type of lens is used to correct far-sightedness?

<p>Converging lens (biconvex) (D)</p> Signup and view all the answers

What is the term for the process of separating a wave, such as light, into its constituent parts?

<p>Dispersion (D)</p> Signup and view all the answers

What is the purpose of converging lenses in optical devices?

<p>To focus light rays to a point (D)</p> Signup and view all the answers

What is the result of light refraction through a triangular prism?

<p>The light is separated into its component colors (A)</p> Signup and view all the answers

What is the application of lenses in devices such as microscopes and telescopes?

<p>To magnify images (B)</p> Signup and view all the answers

What is responsible for the separation of light into its component colors in a rainbow?

<p>All of the above (D)</p> Signup and view all the answers

What occurs when light from the Sun enters a raindrop?

<p>It is refracted and split into its component colors (A)</p> Signup and view all the answers

What is the purpose of a converging lens?

<p>To bend light rays inward, focusing them to a point (D)</p> Signup and view all the answers

Which type of lens is used to correct near-sightedness?

<p>Diverging lens (C)</p> Signup and view all the answers

What is the result of light refracting through a prism?

<p>The light is split into its component colors (A)</p> Signup and view all the answers

What is the primary function of lenses in optical devices?

<p>To correct vision and magnify images (D)</p> Signup and view all the answers

What is the term for the process of bending light around a corner or through a small opening?

<p>Diffraction (D)</p> Signup and view all the answers

What occurs when light hits the back of a raindrop?

<p>It is reflected back into the air (B)</p> Signup and view all the answers

Which type of lens is used to correct far-sightedness?

<p>Converging lens (B)</p> Signup and view all the answers

What is the result of light refracting through a converging lens?

<p>The light is focused to a point (C)</p> Signup and view all the answers

What is the purpose of a diverging lens?

<p>To bend light rays outward, making them spread apart (C)</p> Signup and view all the answers

What is the main reason for the formation of a rainbow?

<p>All of the above (D)</p> Signup and view all the answers

What is the purpose of a converging lens?

<p>To bend light rays inward to a focal point (B)</p> Signup and view all the answers

What is the correction for near-sightedness?

<p>Diverging lens (biconcave) (A)</p> Signup and view all the answers

What is the term for the process of light bending as it passes from one medium to another?

<p>Refraction (B)</p> Signup and view all the answers

What is the main application of lenses?

<p>To correct vision and magnify images (C)</p> Signup and view all the answers

What happens to light as it exits a raindrop?

<p>It is refracted again (D)</p> Signup and view all the answers

What is the main characteristic of a diverging lens?

<p>It bends light rays outward, making them spread apart (B)</p> Signup and view all the answers

What is the process of separating a wave, such as light, into its constituent parts?

<p>Dispersion (C)</p> Signup and view all the answers

What is the main difference between converging and diverging lenses?

<p>The direction of light bending (D)</p> Signup and view all the answers

What is the result of the refraction, reflection, and dispersion of light in a raindrop?

<p>A rainbow (C)</p> Signup and view all the answers

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