CLASS 7 Electricity AND MAGNETISM: Current, Circuits, and Effects

What is the fundamental property of matter related to electricity?

Which of the following describes the interaction between like electric charges?

What is the flow of electric charge called?

In what unit is electric current measured?

What is the conventional direction of electric current flow?

What is an electric circuit?

Which component is NOT typically part of a simple electric circuit?

What type of material allows electric current to flow easily?

What effect is produced when electric current flows through a conductor?

What effect of electric current is used in electric motors?

Which of the following is an example of a natural magnet?

What is a characteristic property of magnets?

How do like poles of magnets interact with each other?

What is the region around a magnet where magnetic force is detected called?

What direction do magnetic field lines point?

What phenomenon links electricity and magnetism?

What is an electric cell also known as?

What is the role of electrical wiring in an electric circuit?

What is a material called if it does not allow electric current to flow through them?

What are the two properties of a bar magnet?

How does increasing the number of turns in the coil of an electromagnet affect its magnetic field strength?

Why are appliances in homes typically wired in a parallel arrangement?

What happens to a bar magnet if it is broken into two pieces?

Which of the below materials is most likely to be used as an insulator in electrical applications?

How does increasing the current passing through the coil of an electromagnet affect its magnetic field?

What is the purpose of the magnetic compass in navigation and orientation?

Which of the following describes the relationship between electric current and magnetism?

What happens to the direction of a freely suspended bar magnet?

Why is it important to take precautions when switching on an electrical circuit?

How can one distinguish between a magnet and a soft iron bar of similar appearance without any additional equipment?

What role does electrical wiring play in an electric circuit?

In the context of a simple electric bell, what happens when the circuit is broken?

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

What is the significance of magnetic declination?

Which of the following best describes the relationship between conductors and insulators regarding electric current?

What represents the electric cell in an electrical circuit?

An electric bulb in a circuit relies on which effect of electric current to produce light?

In relation to electricity, what defines current?

When testing a rod to determine if it's a magnet, what indicates that the rod is indeed a magnet?

What happens to the strength of the magnetic field as the distance from a magnet increases?

In a complex circuit with multiple resistors and voltage sources, which of the following methods is LEAST effective for determining the current through a specific resistor?

A copper wire and a nichrome wire, both of the same length and diameter, are connected in series in an electric circuit. Which wire will generate more heat when current flows through them, and why?

Consider two identical bar magnets. If one is heated to its Curie temperature and then cooled in the absence of an external magnetic field, what will be the expected difference in their magnetic properties?

In a scenario where a transformer is used to step down voltage, what happens to the current in the secondary coil compared to the primary coil, assuming an ideal transformer with no energy losses?

If a charged particle is moving perpendicular to a uniform magnetic field, what is the nature of the force acting on it, and how does this force affect the particle's kinetic energy?

How does the introduction of a ferromagnetic core into a solenoid affect the magnetic field inside the solenoid, and why?

In an RLC series circuit at resonance, what is the phase relationship between the voltage and the current, and how does this affect the power factor of the circuit?

Consider two parallel wires carrying current in opposite directions. How does the magnetic force between the wires vary with the distance between them, and is the force attractive or repulsive?

What is the underlying principle behind the operation of an electrical generator, and how is mechanical energy converted into electrical energy?

Suppose you have a current-carrying wire that forms a single loop. If you increase the area of the loop without changing the current, how does the magnetic dipole moment of the loop change, and what does this imply for its interaction with an external magnetic field?

Electric charge is a fundamental property of matter.

Like charges attract each other.

Electric current is measured in volts (V).

The direction of electric current is from positive to negative.

A circuit consists of a conductor, a switch, and a source of electricity.

Insulators allow electric current to flow through them easily.

The heating effect of electric current is used in devices such as electric bulbs and heaters.

Natural magnets are always artificially magnetized.

Magnets have only one pole (north).

Like poles of magnets attract each other.

A magnetic field is strongest farthest away from a magnet.

Electromagnetism relates electricity and magnetism.

A battery is a junction of cells put together.

Metals are generally poor conductors of electricity.

The magnetic field is the space around a magnet in which the magnetic needle of the magnet gets influenced.

Electric current is defined as the flow of electrons from the negative terminal to the positive terminal in a circuit.

In an electric circuit, insulators are used to facilitate the flow of electric current by providing a low-resistance path.

The heating effect of electric current is only observed in high-power devices like electric heaters and is negligible in low-power devices like LED bulbs.

Electromagnets are permanent magnets that retain their magnetic properties even after the electric current is switched off.

If a bar magnet is broken into two pieces, you will end up with two separate magnets, each with only one pole: one with a north pole and the other with a south pole.

The strength and direction of a magnetic field around a conductor carrying electric current are constant and do not change with the magnitude or direction of the current.

A material can be easily identified as a magnet by observing if it attracts any metal, because all metals are attracted to magnets.

In the context of home electrical circuits, appliances are arranged in a series configuration to ensure each receives the same amount of current, optimizing power usage.

Magnetic declination is the angle between the geographic north and the magnetic south.

The primary purpose of electrical wiring is to insulate components in a circuit, preventing electricity from escaping the designated path.

Increasing the number of turns in the coil of an electromagnet will decrease the strength of its magnetic field.

Electrical switches are designed to introduce continuity in an electrical circuit, thereby preventing the flow of electricity between components

Metals are generally bad conductors of electricity, and thus, materials such as rubber and glass are generally preferred for electrical wiring.

The two key properties of a bar magnet are its ability to attract large objects and its tendency to align in the east-west direction when suspended freely.

Electric cells or dry cells only have one terminal because they don't need a complete circuit to function.

The direction of electric current is defined as flowing from the negative terminal to the positive terminal in a circuit.

Materials with high electrical resistance are classified as conductors, facilitating easy current flow.

The strength of an electromagnet's magnetic field is solely determined by the number of turns in the coil, irrespective of the current passing through it.

If a bar magnet is broken into two parts, each part will temporarily lose its magnetic properties before regaining them.

Magnetic declination refers to the angle between the geographic north and the magnetic south.

In a parallel circuit, if one appliance fails, the total voltage supplied to other appliances significantly increases.

Electrical switches operate by modulating the capacitance within a circuit to control current flow.

Electromagnetism explains how varying gravitational fields produce electric current.

Electric current measures the total number of electrons passing a point per second.

The primary function of an electric bulb is to convert electrical energy into kinetic energy.

[Blank] charges repel each other, while opposite charges attract each other.

Electric ______ is measured in amperes (A).

An electric ______ is a path through which electric current flows.

[Blank] are materials that allow electric current to flow through them easily.

[Blank] are materials that do not allow electric current to flow through them.

When electric current flows through a conductor, it produces ______.

When electric current flows through a conductor, it produces a ______ field.

[Blank] magnets are materials that are naturally magnetized.

[Blank] magnets are materials that are magnetized artificially.

Magnets have two poles: north and ______.

Like poles ______ each other, while opposite poles attract each other.

A ______ field is the region around a magnet where the magnetic force can be detected.

[Blank] is the phenomenon by which an electric current produces a magnetic field.

A ______ is a collection of cells put together.

In homes, appliances are connected in ______ arrangements.

The heating effect of electric current is used in devices such as electric ______ and heaters.

According to the properties of magnets, like poles ______ each other, while opposite poles attract each other.

[Blank] is the phenomenon by which an electric current produces a magnetic field, forming the basis for technologies like motors and generators.

Non-metals are generally bad conductors or ______ of electricity, whereas metals are good conductors due to their free electrons.

The two properties of a bar magnet are its attractive property to small pieces of iron and its ______ property, where it rests in the north-south direction when suspended freely.

If a bar magnet is broken in the middle, each part still acts as a magnet, demonstrating that poles exist in ______.

A magnetic ______ is used to locate directions and contains a small magnetic needle pivoted at the center of a brass box.

An ______ is a temporary magnet that is created by winding a wire around a soft iron core and passing electric current through it.

Increasing the total number of turns of the coil or increasing the strength of the current passing through the coil are two methods to increase the strength of the magnetic field of an ______.

[Blank] is the angle between the magnetic north and the geographic north on the horizontal plane.

The rate of flow of charge is defined as ______ which describes the amount of charge flowing in one second.

Electric cells and ______ are the source of electricity.

The path along which electricity flows is called an ______ circuit.

Appliances in our homes are connected in ______ arrangements so that each works independently and is not affected if another appliance is out of order.

When switching on an electric circuit, it is crucial to avoid touching any component with wet hands and ensure that connecting wires are properly ______.

The phenomenon by which an electric current produces a magnetic field is known as ______, a principle underlying technologies such as electric motors and transformers.

In electrical circuits, appliances are connected in ______ arrangements to ensure independent operation and prevent disruptions to other appliances if one fails.

Materials that impede the flow of electric current, offering significant opposition, are classified as ______, and are characterized by a scarcity of free electrons.

The angle in the horizontal plane between the magnetic north indicated by a compass and the geographic north is termed ______, which varies depending on location.

When a bar magnet is cleaved into multiple segments, each fragment retains magnetic properties, demonstrating that magnetic poles exist in ______.

An ______ is created by winding a wire around a soft iron core, which produces a magnetic field when electric current passes through it, allowing temporary magnetization.

The two key properties exhibited by bar magnets are its capacity to attract small pieces of iron, referred to as its attractive property, and its tendency to align along the ______ axis when freely suspended.

The rate of flow of electric charge through a conductor, quantified as the amount of charge passing a given point per unit time, is defined as electric ______.

To ensure the safe operation of electrical circuits, one should avoid touching switches or components with wet hands and ensure that connecting wires are adequately ______ to prevent shocks.

While metals typically serve as effective conductors, ______, are generally poor conductors due to their limited availability of free electrons.

What are the two types of electric charges?

What unit is electric current measured in?

What three components does a basic electric circuit consist of?

What is a material that allows electric current to flow through it called?

Name a device that uses the heating effect of electric current.

What effect does electric current have on a conductor, causing it to produce a magnetic field?

Give an example of a natural magnet.

Give an example of an artificial magnet.

What are the two poles of a magnet called?

What is the region around a magnet where magnetic force can be detected called?

What is the phenomenon by which electric current produces a magnetic field called?

What is a collection of cells put together called?

What kind of materials are generally bad conductors of electricity?

A freely suspended magnet will rest in what direction?

Increasing what two factors can increase the strength of an electromagnet?

Explain why a bird can sit harmlessly on a high-voltage power line, but a person touching the same line would likely be electrocuted.

Describe how an electromagnet works and list two factors that can increase its strength.

Explain the difference between a conductor and an insulator, giving an example of each.

What is magnetic declination?

Describe how you could determine if an unmarked metal bar is a permanent magnet or just a piece of iron.

Explain why appliances in a home are connected in parallel rather than in series.

Describe 'electromagnetism' and give an example of a technology that relies on it.

If you break a bar magnet in half, do you get two separate north and south poles? Explain.

State two precautions one must take when switching on an electric circuit.

A circuit contains a battery, a switch, and a lamp. Explain what happens when the switch is closed.

How does an electric bell work?

Explain why some materials are good conductors of electricity while others are insulators.

Describe the relationship between electric current and magnetic fields.

What is electric current and in what units is it measured?

Explain, using the concept of electron mobility, why metals are generally good conductors of electricity, while non-metals are not.

Describe how the introduction of impurities into a semiconductor material can alter its electrical conductivity. Provide examples of n-type and p-type doping.

Explain why a bird can sit harmlessly on a high-voltage power line, but a person touching the same line would likely be electrocuted. Use the concept of potential difference.

Describe in detail how varying the number of turns in the coil and the current passing through it affects the strength of an electromagnet and why these changes occur.

Explain, based on magnetic domain theory, how a ferromagnetic material becomes magnetized and why it can retain magnetism even after the external magnetic field is removed.

Explain how a magnetic compass works by detailing the interaction between the compass needle and Earth's magnetic field.

Discuss why appliances in homes are connected in a parallel arrangement rather than in series within electrical circuits, especially, comment on the impact of voltage and current distribution.

Describe the relationship between magnetic declination and geographic north. Why is understanding declination important for accurate navigation?

Explain how the heating effect of electric current is utilized in a common household appliance. Include details of the energy conversions involved and any safety mechanisms present.

Given two unmarked bars, one a magnet and the other soft iron, describe a method to distinguish between them without using any additional materials or equipment. Why does this method work?

Consider a scenario where a superconducting ring is placed in a magnetic field. If the magnetic flux through the ring is then manipulated to oscillate sinusoidally with time, describe, using the principles of flux quantization and the London equations, the behavior of the supercurrent within the ring. Furthermore, what observable macroscopic quantum phenomena might arise from this manipulation, and how would their characteristics depend on the amplitude and frequency of the flux oscillations?

Imagine you have constructed a complex circuit composed of both linear and non-linear elements, including a memristor characterized by a highly hysteretic I-V curve. If a specific waveform is applied as input, detail how you would derive, both analytically and computationally, the circuit's response, accurately accounting for the memristor's history-dependent behavior and its impact on the overall circuit dynamics.

Envision a scenario involving a parallel-plate capacitor with a dielectric material exhibiting strong frequency-dependent permittivity. If the capacitor is subjected to a high-frequency alternating voltage, explain how the dielectric's relaxation phenomena and associated losses would affect the capacitor's impedance, power dissipation, and overall performance. What specific experimental techniques could be employed to accurately characterize the dielectric's behavior across a broad frequency range, and how would the data obtained be interpreted to optimize the capacitor's design for high-frequency applications?

Consider an electromagnetic wave propagating through a complex medium exhibiting both spatial dispersion (non-local response) and temporal dispersion (frequency-dependent response). Elaborate on how these dispersive effects, coupled with potential non-linearities in the medium's response, would alter the wave's propagation characteristics, leading to phenomena like self-focusing, pulse broadening, and the generation of new frequency components. Further, discuss the theoretical frameworks and computational techniques needed to accurately model and predict the wave's behavior under these intricate conditions.

Describe the intricacies involved in designing a high-efficiency wireless power transfer system operating in the near-field regime, intended to power deeply implanted medical devices. Your response should encompass the optimization strategies for both the transmitter and receiver coils, accounting for the effects of tissue absorption, regulatory constraints on electromagnetic field exposure, and the need for robust and reliable power delivery despite variations in device orientation and tissue properties. What specific modulation and control techniques could be implemented to maximize power transfer efficiency and ensure patient safety?