(English Medium) ICSE Class 10 - CISCE Question Bank Solutions

State the two properties of the magnetic lines of force around a circular coil.

A straight wire is held vertical and current is passed in it in the upward direction. A compass needle is kept near the wire in north of it. How is the needle deflected? What is the change in the deflection of the needle if the current in wire is reversed?

Describe a simple Experiment to demonstrate that there Exists a magnetic field around a current-carrying conductor. 

A straight current-carrying conductor is kept in a magnetic field. It Experiences a force. State three factors on which the magnitude of force Experienced by the conductor depends. Under what condition will the conductor Experience no force?

State the purpose of the iron core.

How does a magnetic field set up by a solenoid change when number of turns are increased?

How does a magnetic field set up by a solenoid change when a soft iron core is inserted inside solenoid?

How does a magnetic field set up by a solenoid change when strength of current in the solenoid is decreased?

Why is soft iron generally used as the core of the electromagnet?

State the condition when an electric charge can give rise to a magnetic field.

What is a permanent magnet? Give one use of it.

State two advantages of an electromagnet over a bar magnet.

What will be the effect on the working of an electric bell if instead of a direct current an alternating current is used?

State three factors which govern the speed of rotation of an electric motor.

What energy conversion takes place during the working of a d c motor?

State the factors that can increase the speed of rotation of the coil in a D.C. motor.

State the energy change that takes’place in a D. C. motor.

State the principle of a D. C. motor.

State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting an the coil is maximum.

State the position of armature coil relative to the direction of magnetic field, in a D. C. motor when the deflecting couple acting and the coil is minimum.