A transformer has 1000 turns on the primary coil. The voltage applied to the primary coil is 230V a. c,
How many turns are on the secondary coil if the output
voltage is 46 V a. c.?
A)20 B)200 C)2000 D4000 E)8000

200

Explanation:

Given parameters:

Number of turns in primary coil  = 1000 turns

Primary voltage  = 230V

Secondary voltage  = 46V

Unknown:

Number of turns in secondary coil = ?

Solution:

To solve this problem, we have to use the expression for solving problems related with transformers;

          =  

Vs is the secondary voltage

Ns is the number of secondary turns

Vp is the primary voltage

Np is the number of primary turns

 Now insert the parameters and solve;

            =

          46 x 1000 = 230Ns

             Ns = 200

0.55x745.7j and a calculator