Question

A step-down transformer has a coil ratio of $1.5$ to $17$. The voltage applied at the primary side of the transformer is $136V$. What is the output voltage of the transformer?

• A. $1.2V$
• B. $1.5V$
• C. $5.25V$
• D. $12V$
• E. $18.75V$

Answer 1

The correct option is D $12V$

As it is a step-down transformer so number of turns in primary will be greater than secondary .

Given - $N_S=1.5$ , $N_P=17$ , $V_P=V_{IN}=136V$ ,

we have transformation ratio , $N_S/N_P=V_{OUT}/V_{IN}$ ,

$1.5/17=V_{OUT}/136$ ,

or $V_{OUT}=1.5\times 136/17=12V$