Question

A transformer is to be used to provide power for a computer disk drive that needs 5.2 V (rms) instead of the 120 V (rms) from the wall outlet. The number of turns in the primary is 410, and it delivers 500 mA (the secondary current) at an output voltage of 5.2 V (rms). (a) Should the transformer have more turns in the secondary compared to the primary, or fewer turns?

Answer 1

Fewer turns

Step-by-step explanation:

The secondary voltage is given as 5.2 V and the voltage from the wall outlet that is primary voltage is 120 V

We have also given number of turns in primary is 410

We know the equation for transformer
`(V_1)/(V_2)=(N_1)/(N_2)`

`(120)/(5.2)=(410)/(N_2)`

`N_2=17.76`

As the number of turns can not be fraction so
`N_2=18` so transformer should fewer turns at secondary as compared to primary