Question

A transformer working on a 240 V A.C. supplies a voltage of 8 V to an electric bell. The number of turns in primary coil is 4800. What is the number of turns in the secondary coil?

• A. 2400
• B. 160
• C. 800
• D. 600

Answer 1

The correct option is B 160

According to the question,
${\text{V}}_p$ = 240 V ${\text{V}}_s$ = 8 V
$n_p$ = 4800 $n_s$ = ?
We know that, $\frac{n_s}{n_p}=\frac{{\text{V}}_s}{{\text{V}}_p}$
$\Rightarrow$ $\frac{n_s}{4800}=\frac{8}{240}$
$\Rightarrow$ $n_s$ = $\frac{8}{240}\times 4800$
$n_s$ = 160 turns