General Science Examination 2023
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Questions and Answers

Number of seconds in 4hrs are ______.

  • 24
  • 360
  • 600 (correct)
  • 240

Mirror has ______ opaque surface.

  • zero (correct)
  • infinite
  • two
  • one

What are insulators?

Materials that resist the flow of heat or electricity

Pure water is bad conductor of electricity. Give reason.

<p>Pure water does not have any free ions to carry the charge.</p> Signup and view all the answers

Define Spectrum of light.

<p>It is range of all colors present in white light, from violet to red, and its arrangement by wavelength.</p> Signup and view all the answers

What effect of current causes the bulb to glow?

<p>The heating effect of the current causes the filament to glow.</p> Signup and view all the answers

Which of the following mirrors are used in a periscope?

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

Converging mirror is also known as

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

The light travels with speed of ______.

<p>3 x 10⁸ m/s</p> Signup and view all the answers

Define motion.

<p>Change in position of an object with respect to time.</p> Signup and view all the answers

Shape of distance time graph for uniform motion is always _______.

<p>straight line</p> Signup and view all the answers

What is fuse?

<p>A safety device that protects electrical circuits from overcurrents.</p> Signup and view all the answers

How does heat travel in solid?

<p>Heat travels in solids through conduction</p> Signup and view all the answers

Write two devices which work on heating effect of electric current.

<p>Electric iron and electric heater</p> Signup and view all the answers

Why pan became red hot?

<p>Because of heating effect of electricity, the pan attained high temperature and glowed red.</p> Signup and view all the answers

The units to measure current is ______.

<p>Ampere</p> Signup and view all the answers

What values was shown by Sonal?

<p>Sonal showed presence of mind, responsibility and concern towards her mother.</p> Signup and view all the answers

Define reflection?

<p>It is the bouncing back of light from the surface of a material.</p> Signup and view all the answers

When two mirrors are kept parallel to each other, no of images formed are_.

<p>Infinite number of images</p> Signup and view all the answers

What do you mean by dispersion of light?

<p>It is the splitting of white light into its component colors.</p> Signup and view all the answers

Assertion: The time taken to complete one oscillation is called the time period of the pendulum. Reason: For a pendulum of a particular length, the time period is not constant.

<p>If Assertion is true but Reason is false. (D)</p> Signup and view all the answers

Assertion: Convex mirror is used as a rear view mirror in vehicles. Reason: The nature of the image formed by a convex mirror is virtual and diminished in size.

<p>If both Assertion and Reason are true and Reason is the correct explanation of Assertion. (B)</p> Signup and view all the answers

The filament of an electric blub is made up of

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

Define uniform and non-uniform motion and give an example of each

<p>Uniform motion is a motion in which an object travels at a constant speed in the same direction. For example, a car traveling at 60 km/h on a straight road is an example of uniform motion. Non-uniform motion is a motion in which an object changes its speed or direction or both. For example, a car accelerating from rest or turning a corner is an example of non-uniform motion.</p> Signup and view all the answers

How much time will a car take to cover a distance of 300km, if the speed of the car is 50km/h?

<p>The car will take 6 hours to cover 300km.</p> Signup and view all the answers

What is the purpose of installing an MCB in a circuit?

<p>MCBs are used to protect electrical circuits from overloads and short-circuits</p> Signup and view all the answers

What is dispersion of light.

<p>The splitting of white light into its component colors when it passes through a prism or a medium with a varying refractive index.</p> Signup and view all the answers

State the factors affecting the heat generated in a current carrying wire?

<p>The factors affecting heat generated in a current-carrying wire include the magnitude of the current flowing through the wire, the resistance of the wire, and the time for which the current flows.</p> Signup and view all the answers

What is the significance of the slope of a straight line graph?

<p>The slope of a straight line graph represents the rate of change of the dependent variable with respect to the independent variable.</p> Signup and view all the answers

What is a simple pendulum? How can you determine the time period of a simple pendulum?

<p>A simple pendulum consists of a small bob of mass (m) suspended from a fixed point (O) by a light, inextensible string. The time period of a simple pendulum is defined as the time it takes for the pendulum to complete one full oscillation, or one swing back and forth. The time period can be determined by simply measuring the time taken for multiple oscillations and dividing by the number of oscillations.</p> Signup and view all the answers

Explain the terms amplitude and time period.

<p>Amplitude is the maximum displacement of the oscillating object from its equilibrium position. The time period of an oscillation is the time taken by the object to complete one full oscillation.</p> Signup and view all the answers

A. Draw the graph for the motion of the student going to school on a crowded road

<p>The graph would show a non-uniform motion as the student's speed would vary due to the crowd.</p> Signup and view all the answers

B. A bus travels 20km in 15 min. Express the speed in km/h and m/s

<p>The speed of the bus is 80 km/h and 22.22 m/s.</p> Signup and view all the answers

Give reasons for the following: a) Speed of a moving object can never be zero. b) Filament blubs are not power efficient. c) The word AMBULANCE is written backwards on an ambulance. d) Steel cannot be used in electromagnets. e) Concave mirror is used as a shaving.

<p>a) An object is said to be in motion if its position changes with time, so if an object is moving, even at a very slow speed, its speed cannot be zero. b) Light bulbs use a significant amount of energy to produce light, so they are considered to be power inefficient. c) The word AMBULANCE is written backwards on an ambulance so that drivers in oncoming traffic can read it correctly in their rearview mirror. d) Steel is a ferromagnetic material, which means it is attracted to magnets, so it cannot be used to make electromagnets. e) Concave mirrors can form magnified images, which makes them suitable for shaving mirrors.</p> Signup and view all the answers

A. With the help of a ray diagram explain the concept of converging and diverging mirror.

<p>A converging mirror, also known as a concave mirror, brings parallel rays of light to a focus. A diverging mirror, also known as a convex mirror, spreads out parallel rays of light making them appear to diverge from a focal point behind the mirror. Refer to the diagram for a visual explanation.</p> Signup and view all the answers

B. Explain the working of an electric bell with the neat labelled diagram.

<p>An electric bell is a device that produces sound when an electric current flows through it. When the switch is closed, the circuit is complete, and the electromagnet attracts the hammer. This attracts the hammer toward the gong and causes it to strike it, producing a sound. The hammer then moves away from the gong, breaking the circuit, which causes the electromagnet to lose its magnetic field. The hammer is then pushed back by the spring, completing the circuit again, and the process repeats. Refer to the diagram for a visual explanation.</p> Signup and view all the answers

Flashcards

Time period of a pendulum

The time taken for one complete oscillation of a pendulum.

Insulator

A material that does not allow electricity to flow through it easily.

Heating effect of current

The effect of electric current that causes a bulb to glow due to heat produced by the filament.

Converging mirror

A mirror with a curved reflecting surface that converges incoming light rays.

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Motion

The change in the position of an object with respect to a reference point.

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Fuse

A device that breaks a circuit when the current exceeds a safe limit.

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Heat transfer in solids

The process of heat transfer through a material without any movement of the material itself.

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Devices that use heating effect of current

Devices that use the heating effect of electric current, like electric heaters and toasters.

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Reflection

The process by which light bounces off a surface.

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Convex mirror

A mirror with a curved reflecting surface that spreads out incoming light rays.

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Dispersion of light

The separation of white light into its constituent colors (red, orange, yellow, green, blue, indigo, violet).

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Factors affecting heat generated in a current-carrying wire

The amount of heat produced in a current-carrying wire depends on the amount of current flowing, the resistance of the wire, and the time for which the current flows.

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Simple pendulum

A simple pendulum consists of a small bob suspended from a fixed point by a string or light rod.

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Amplitude

The maximum displacement of the bob from its mean position.

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Time period

The time taken by the bob to complete one oscillation.

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Uniform motion

A type of motion where the speed of the object remains constant.

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Non-uniform motion

A type of motion where the speed of the object changes.

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Significance of slope in a distance-time graph

The slope of a distance-time graph represents the speed of the object.

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MCB (Miniature Circuit Breaker)

A circuit breaker designed to protect electrical circuits from overcurrents.

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Converging mirror

A type of mirror that converges incoming light rays towards a focal point.

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Diverging mirror

A type of mirror that spreads out incoming light rays.

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Why is "AMBULANCE" written backwards on an ambulance?

The word "AMBULANCE" is written backward on an ambulance so that drivers approaching from the opposite direction can read it in their rearview mirror.

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Why steel cannot be used in electromagnets?

Steel is a magnetic material, but its magnetism is weak and difficult to control. This makes it unsuitable for electromagnets.

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Why filament bulbs are not power efficient?

Filament bulbs are not power efficient because they waste a lot of energy as heat.

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Why concave mirrors are used for shaving

A concave mirror used in shaving because it produces a magnified image of the face.

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Why speed of a moving object can never be zero?

The speed of a moving object can never be zero because it implies that the object is not changing its position with respect to a reference point.

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Working of an electric bell

An electric bell works by using an electromagnet to strike a hammer against a bell when the circuit is closed.

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Study Notes

General Instructions

  • The exam has 5 sections (A, B, C, D, and E).
  • There are 25 questions in total.
  • All questions are compulsory.
  • Internal options are available for some questions (questions 3, 7, 16, 23, and 25).
  • Section A has short answer questions (1-10), each worth 1 mark.
  • Section B has case study questions (11-12), each worth 4 marks. Attempt 4 sub-parts per question.
  • Section C has multiple choice and assertion-reason questions (13-15), each worth 1 mark.
  • Section D has higher-order thinking/application/source/diagram questions (16-17), each worth 2 marks.
  • Section E has short and long answer questions (18-25), with varying marks (2, 3, and 5 marks).
  • Diagrams should be labeled.

Section A - Very Short Answer (1 mark each)

  • Question 1: Number of seconds in 4 hours: 14400 seconds.
  • Question 2: Mirrors have one/two surfaces.
  • Question 3: Pure water is a bad conductor of electricity. Explain the reasoning for this.
  • Question 4: Definition of light spectrum.
  • Question 5: Effect of current that causes a bulb to glow.
  • Question 6: Which type of mirror is used in a periscope? (Concave)
  • Question 7: Converging mirror is also known as what type of mirror? (Concave mirror)
  • Question 8: Define motion.
  • Question 9: Shape of the distance-time graph for uniform motion.
  • Question 10: What is a fuse?

Section B - Case Study (4 marks each)

  • Question 11: Sonal noticed a hot tea pan. Elaborate on heat transfer and electric current's heating effect.
  • Question 11 (i): Describe heat transfer in solids.
  • Question 11 (ii): Name two devices working on heating effects of electric current.
  • Question 11 (iii): Reason why the pan became red-hot.
  • Question 11 (iv): Units to measure electric current.
  • Question 11 (v): What values does Sonal demonstrate?
  • Question 12: Rohan visits a science park. Define reflection.
  • Question 12 (i): Define reflection.
  • Question 12 (ii): Sketch a diagram of a convex mirror.
  • Question 12 (iii): Number of images formed when two parallel mirrors are placed.
  • Question 12 (iv): Explain dispersion of light.
  • Question 12 (v): Rohan's values displayed in the park visit.

Section C - Multiple Choice/Assertion-Reason (1 mark each)

  • Question 13: Assertion: Time taken to complete one oscillation (pendulum) is constant. Reason: .... .
  • Question 14: Assertion: Convex mirrors are used as rear-view mirrors. Reason: ...
  • Question 15: The filament of an electric bulb is made of... . (tungsten)

Section D - Higher Order Thinking (2 marks each)

  • Question 16: Define uniform and non-uniform motion. Provide an example of each.
  • Question 16 (or): Calculate the time taken by a car to travel 300 km at 50 km/hr.
  • Question 17: Purpose of installing an MCB (mini-circuit breaker) in a circuit.

Section E - Short and Long Answer (2, 3, or 5 marks each)

  • Question 18: Explain dispersion of light.
  • Question 19: State factors affecting heat generated in a current-carrying wire.
  • Question 20: Significance of the slope in a straight-line graph.
  • Question 21: Simple pendulum and determining its time period – steps/methodology.
  • Question 22: Define amplitude and time period.
  • Question 23: Graph on a student's commute, crowded road.
  • Question 24: Reasons for the following: Speed of a moving object cannot be zero, Filament bulbs are not power-efficient, Ambulance word written backwards, Steel cannot be used in electromagnets, Using concave mirrors for shaving.
  • Question 25: Concept of converging/diverging mirrors using ray diagrams or workings of an electric bell with labeled diagram.

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Description

This quiz comprises 25 compulsory questions divided into five sections, challenging students' understanding of various science concepts. It includes short answers, case studies, multiple choice, and application-based questions. Prepare thoroughly as each section tests different skill levels and comprehension.

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