Question

The input AC voltage to the transformer is $3$ kV and output is $100$ V. Then:

• A. The ratio of number of turns in the primary to secondary coil is $30:1$
• B. The transformer is a step down transformer
• C. The transformer is a step up transformert
• D. Both $1$ and $2$

Answer 1

The correct option is D Both $1$ and $2$

D

Given,

Voltage across the primary winding, $V_1=3kv=3000V$

Voltage across the secondary winding, $V_2=100V$

Here it is asked to find out the ratio of number of turns in the primary coil to secondary coil

We have,

$\frac{N_1}{N_2}=\frac{V_1}{V_2}$

Then,

$\frac{N_1}{N_2}=\frac{3000}{100}$

$\frac{N_1}{N_2}=\frac{30}{1}$

$N_1:N_2=30:1$

The ratio of number of turns in the primary coil to secondary coil is $30:1$

Since the input voltage of the transformer is 3kv and the output voltage is 100 V this is a step down transformer.