Question

A transformer with a $110V$ primary has a $15:1$ turns ratio. The load resistance, $R_L$, is $120$ . What is the approximate voltage across the load?

• A. $7.3V$
  
• B. $73V$
  
• C. $88V$
  
• D. $880V$
  

Answer 1

The correct option is A $7.3V$

Solution:-

In transformers:-

$\frac{V_P}{V_S}=\frac{N_P}{N_S};\frac{N_P}{N_S}$ is ratio of turns in primary $\&$ secondary coils.

$V_S={\frac{N_P}{N_S}}^{-1}.V_P$ Given:- primary voltage$\left(V_P\right)$ = 110V

$V_S=\frac{1}{15}\times 110=7.3V$ $N_P:N_S=15:1$

$V_S=7.3V$