Question

For a transformer, the turns ratio is $3$ and its efficiency is $0.75$. The current flowing in the primary coil is $2A$ and the voltage applied to it is $100V$. Then the voltage and the current flowing in the secondary coil are _________ respectively.

• A. 150 V, 1.5 A
• B. 300 V, 0.5 A
• C. 300 V, 1.5 A
• D. 150 V, 0.5 A

Answer 1

Answer: (B)

Given, $\frac{n_s}{n_p}=3;\eta =0.75;l_p=2A$ and $V_p=100V$
We know that,
$\eta =\frac{V_S}{V_P}\frac{l_S}{l_P}$
Or $\eta =\left(\frac{n_S}{n_P}\right)\frac{l_s}{l_P}\left(\because \frac{n_s}{n_p}=\frac{V_s}{V_D}\right)$
$\Rightarrow 0.75=\frac{3\times l_s}{2}$
$\Rightarrow l_s=0.5A$
By the relation, $\frac{n_s}{n_P}=\frac{V_s}{V_P}$
$\Rightarrow 3=\frac{V_s}{100}$
$\Rightarrow V_s=300V$