Question

An ideal step-down transformer is needed to reduce a primary voltage of 120 V to 6.0 V. What must be the ratio of the number of turns in the secondary to the number of turns in the primary

Answer 1

Answer:

$N_s : N_p = 20 : 1$

Explanation:

From the question we are told that

    The primary voltage is  $V_p = 120 \ V$

     The secondary voltage is  $V_s = 6 \ V$    

     

Generally from the transformer equation we have that

        $\frac{V_p}{V_s} = \frac{N_p}{N_s}$

So

       $\frac{120}{6} = \frac{N_p}{N_s}$

=>      $\frac{N_p}{N_s} = 20$

Therefore the ratio of the number of turns in the secondary to the number of turns in the primary is  

       $N_s : N_p = 20 : 1$