Exercise

An electron enters a magnetic field at right angles to it as shown in figure. The direction of the force acting on the electron will be:

The core of a transformer is laminated, because

The diagram below shows a magnetic needle kept just below the conductor AB which is kept in the North-South direction.

i) In which direction will the needle deflect when the key is closed?

ii) Why is the deflection produced?

iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB?

iv) Name one device which works on this principle.

What is the function of a transformer?

Explain the construction of the transformer. Mention its principle.

How is the emf across primary and secondary coils of a transformer related with the number of turns of coil in them?

State any two reasons for energy loss in a transformer.

State two characteristics of a primary coil of a step-up transformer when compared to the secondary coil.