Question

Stepping up of voltage by a factor of 100,reduce the current by a factor of

• A. 10
• B. 100
• C. leaves the current unchanged
• D. increase the current by a factor of 100

Answer 1

The correct option is B 100

Let the voltage in primary coil of transformer be $V_p$.

Thus voltage in secondary coil of transformer $V_s=100V_p$

Using $P_p=P_s$

$\therefore$ $V_p{I}_p=V_s{I}_s$

Or $V_p{I}_p=\left(100V_p\right)I_s$

$⟹$ $I_s=\frac{I_p}{100}$

Thus current must be reduced by a factor of $100$.