Question

In the method using the transformers, assume that the ratio of the number of turns in the primary to that in the secondary in the step-up transformer is 1 : 10. If the power to the consumers has to be supplied at 200 V, the ratio of the number of turns in the primary to that in the secondary in the step-down transformer is

• A. 200 : 1
• B. 150 : 1
• C. 100 : 1
• D. 50 : 1

Answer 1

The correct option is A 200 : 1

$\frac{V_s}{4000}=\frac{10}{1}$

or $V_s=40000V$

$\frac{N_s}{N_p}=\frac{V_{out}}{V_{in}}=\frac{200}{40000}=\frac{1}{200}$