NCERT solutions for Science [English] Class 10 chapter 13 - Magnetic Effects of Electric Current [2018 edition]

Why does a compass needle get deflected when brought near a bar magnet?

Draw magnetic field lines around a bar magnet.

Write any three properties of magnetic lines of force.

Why don’t two magnetic lines of force intersect each other?

Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.

The magnetic field in a given region is uniform. Draw a diagram to represent it.

The magnetic field inside a long straight solenoid-carrying current ______.

Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.)

In the Activity shown below, how do we think the displacement of rod AB will be affected if

1. current in rod AB is increased
2. a stronger horse-shoe magnet is used
3. length of the rod AB is increased?

A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is ______.

State Fleming’s left-hand rule.

What is the principle of an electric motor?

What is the role of the split ring in an electric motor?

Explain different ways to induce current in a coil.

 State the principle of an electric generator.

Name some sources of direct current.

Which sources produce alternating current?

A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each______.

Name safety measures commonly used in electric circuits and appliances.

An electric oven of 2 kW is operated in a domestic electric circuit (220 V) that has a current rating of 5 A. What result do you expect? Explain.

What precaution should be taken to avoid the overloading of domestic electric circuits?

Which of the following correctly describes the magnetic field near a long straight wire?

The phenomenon of electromagnetic induction is

The device used for producing electric current is called a ______.

The essential difference between an AC generator and a DC generator is that

At the time of short circuit, the current in the circuit ______.

State whether the following statement is true or false.

An electric motor converts mechanical energy into electrical energy.

State whether the following statement is true or false.

An electric motor converts mechanical energy into electrical energy.

State whether the following statement is true or false

The field at the centre of a long circular coil carrying current will be parallel straight lines.

State whether the following statement is true or false.

A wire with a green insulation is usually the live wire of an electric supply.

List two methods of producing magnetic fields.

How does a solenoid behave like a magnet? Can you determine the north and south poles of a current-carrying solenoid with the help of a bar magnet? Explain.

When is the force experienced by a current-carrying conductor placed in a magnetic field largest?

Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, is deflected by a strong magnetic field to your right side. What is the direction of magnetic field?

Draw figure ‘Electric motor’ and working 

What is the Principle of an Electric motor?

What is the function of a split ring in an electric motor?

Name some devices in which electric motors are used

A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is pushed into the coil?

A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is withdrawn from inside the coil?

A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is held stationary inside the coil?

 Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current be induced in the coil B? Give reason.

State the rule to determine the direction of a magnetic field produced around a straight conductor-carrying current.

State the rule to determine the direction of a force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it.

State the rule to determine the direction of a current induced in a coil due to its rotation in a magnetic field.

Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes?

What happens to the flow of electric current during a short circuit?

What is the function of an earth wire?