# Electrical Engineering - Transformers

### Exercise :: Transformers - General Questions

11.

How many primary volts must be applied to a transformer with a turns ratio of 0.1 to obtain a secondary voltage of 9 V?

 A. 9 V B. 90 V C. 900 V D. 0.9 V

Explanation:

We know that, V2/V1 = N2/N1.

Given V2 = 9v, N2/N1 = 0.1

Therefore, 9v/V1 = 0.1

V1 = 9v/0.1 = 90v.

For more detail: Step Down Transformer - Circuit with Simulation.

12.

In a certain loaded transformer, the secondary voltage is one-fourth the primary voltage. The secondary current is

 A. one-fourth the primary current B. four times the primary current C. equal to the primary current D. one-fourth the primary current and equal to the primary current

Explanation:

No answer description available for this question. Let us discuss.

13.

A certain transformer has a turns ratio of 1 and a 0.85 coefficient of coupling. When 2 V ac is applied to the primary, the secondary voltage is

 A. 1.7 V B. 0.85 V C. 1 V D. 0 V

Explanation:

No answer description available for this question. Let us discuss.

14.

The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330 load. The turns ratio is 3:1. What is the secondary voltage?

 A. 2 V B. 20 V C. 180 V D. 18 V

Explanation:

No answer description available for this question. Let us discuss.

15.

The primary winding of a power transformer should always be

 A. open B. shorted C. switched D. fused