Magnetic Effect...

A boy was making a model of an electric bell. He connected the coil in the circuit and switched it on. However, the magnetism produced in the coil was not strong enough. He made some changes in the coil and the circuit was now working.
What changes did the boy make in the coil?

Which of the following figures correctly depicts the direction of magnetic field of a current carrying through a circular loop.

A boy was making a model of electric bell. He connected the coil in the circuit and switched it on. However, the magnetism produced in the coil was not strong enough. He made some changes in the coil and the circuit was now working.
How can you produce strong magnetism without changing the magnet?

Among the following components of electric motor, which component acts as a commutator?

What happens to the strength of the magnetic field if the number of turns is increased?

The speed of the motor can be increased by:

Why is an armature used in electric motor?

In electric motor, which rule is used to find the direction of force on a current carrying conductor in a magnetic field?

What would happen to the direction of rotation of the motor, if the current were reversed.

Which rule is used to find the direction of the induced current?