Selina solutions for Concise Physics [English] Class 7 ICSE chapter 7 - Electricity and Magnetism [Latest edition]

Write true or false for a given statement.

A current-carrying coil, when suspended freely, can rest in any direction.

Write true or false for a given statement.

 A coil carrying current behaves like a magnet.

Write true or false for a given statement.

In an electromagnet, the core is made up of copper.

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An electric bell uses an electromagnet.

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An electromagnet with soft iron core is a temporary magnet.

Write true or false for a given statement.

We use cell as the source of electricity to run an electric immersion rod.

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A torch bulb glows if the terminals of the bulb are connected to the terminals of a cell by the metallic wire

Write true or false for a given statement.

Wool is a conductor of electricity.

Write true or false for a given statement.

Silver is an insulator of electricity.

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Our body is a conductor of electricity.

For a circuit to be complete, every part of it must be made up of conductors.

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All metals are conductors of electricity.

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The switch should not be touched with wet hands.

Write true or false for a given statement.

A switch is an on-off device in an electric circuit.

 Fill in the blank

 A magnet has ______ poles.

Fill in the blank 

Like poles ______ each other and unlike poles _____

Fill in the blank

 An electromagnet is used to separate large mass of ______ scrap.

Fill in the blank

The strength of the magnetic field of an electromagnet is increased by inserting a core of soft ______

Fill in the blank 

In a torch we use ______ as the source of electricity.

Fill in the blank

To light a table lamp and to run a refrigerator, we use ______ as the source of electricity.

Fill in the blank

A group of two or more cells is called a ________.

Fill in the blank

_______ pass electricity through them.

Fill in the blank

_______ do not pass electricity through them.

Match the following

Select the correct alternative

A freely suspended magnet rests in

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Electromagnets are made up of

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An electromagnet is used in 

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The purpose of armature in an electric bell is

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In a torch, the source of electricity is

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Electricity can flow through

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Electricity does not flow through

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We should not touch the switch with wet hands otherwise

State two properties of a bar magnet ?

How will you test whether a given rod is a magnet or not ?

How will you test whether a given rod is made of iron or not?

You are given two similar bars. One is a magnet and the other is of soft iron. How will you distinguish and identify them ?

You are given a magnet. How will you use it to find north-south direction at a place?

Describe a simple experiment to illustrate that like poles of two magnets repel each other while the unlike poles attract ?

“Poles exist in pair”. Comment on this statement ?

What is a magnetic compass ? State its use.

Explain the meaning of the term magnetic field ?

What is an electromagnet?

Name the material of an electromagnet?

Draw a labelled diagram to make a soft iron bar as an electromagnet. Describe in steps the procedure ?

You are given a U shaped soft iron piece, insulated copper wire and a battery. Draw a circuit diagram to make a horse shoe electromagnet ?

Name two factors on which the strength of magnetic field of an electromagnet depends ?

State two ways by which the strength of magnetic field of an electromagnet can be increased ?

State two common uses of electromagnets  ?

Name a domestic device in which an electromagnet is used ?

Draw a neat and labelled diagram of an electric bell and describe its working ?

The incomplete diagram of an electric bell is given in fig. Complete the diagram and label its different parts ?

What is declination ? Draw a diagram to show the angle between the declination and true direction of geographic north.

Define the term current.

Name four appliances which work using electricity ?

Name two sources of electricity.

What is a battery?

What is an electric circuit ?

Describe an experiment to show that electricity flows only if the circuit is complete and it does not flow if the circuit is incomplete.

You are provided with a torch bulb, a cell and two plastic coated f metal wires. Draw a diagram to show a complete circuit to light the bulb.

In which of the following case the bulb will glow :

Distinguish between conductors and insulators of electricity. Give two examples of each.

Select conductors and insulators from the following :
Glass, silver, copper, wood, paper, pure water, impure water, aluminium, iron, leather, plastic, steel, human body and ebonite.

The following diagram shows four circuits A, B, C and D. Each circuit has a cell and a torch bulb. Name the circuits in which the bulb will glow? Give reason to your answer.

The diagram given below shows a bulb connected with a cell having terminals A and B. Mark the direction of current in the bulb.

State the function of each of the following in an electric circuit and draw its symbolic representation: (1) Switch and (2) Cell.

Draw a circuit diagram for a bulb connected to a cell with a switch. Mark arrow in the diagram to indicate the direction of flow of current.

In which arrangement are the appliances connected in the electric circuit of our homes, Series or Parallel ? Give one reason for your answer.

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