Transformer

The core of a transformer is laminated so that:

1.	energy losses due to eddy currents may be minimized
2.	the weight of the transformer may be reduced
3.	rusting of the core may be prevented
4.	the ratio of voltage in primary and secondary may be increased

A transformer is used to light a and lamp from a main. If the main current is the efficiency of the transformer is approximately:
1.
2.
3.
4.

A V input is supplied to a transformer. The output circuit draws a current of A at V. If the efficiency of the transformer is %, the current drawn by the primary windings of the transformer is:
1. A
2. A
3. A
4. A

A step-down transformer connected to an AC mains supply of is made to operate at lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?
1.
2.
3.
4.

A lamp is connected to the secondary of a step-down transformer, whose primary is connected to AC mains of . Assuming the transformer to be ideal, what is the current in the primary winding?
1.
2.
3.
4.

In an ideal transformer, the turns ratio is The ratio is equal to (the symbols carry their usual meaning):
1.
2.
3.
4.