Question

An emf applied to a primary coil is $210V$. If the number of turns in primary coil is $200$ and that in the secondary coil is $20$, then find out the output voltage. Name the type of the transformer.

Answer 1

$E_p=210V;N_p=200;N_s=20E_s=?$
$\frac{E_p}{E_s}=\frac{N_p}{N_s}$
$\therefore \frac{210}{E_s}=\frac{220}{20}=10$
$\therefore E_s=\frac{210}{10}=21V$
Since $E_s<E_p$, it is a step-down transformer.