Physics 2005 JAMB Past Questions - Question 1: A transformer is rated 240 V. If the primary coil is 4000 turns and the secondary voltage 12 V, determine the number of turns in the secondary coil

Correct Answer

D

Explanation

Ns=Es*NP/EP=12*4000/240 =200You can use the transformer turns ratio formula to determine the number of turns in the secondary coil. The formula is:

Turns ratio (Np/Ns) = Primary voltage (Vp) / Secondary voltage (Vs)

In this case:

Primary voltage (Vp) = 240 V
Secondary voltage (Vs) = 12 V

Now, you want to find the number of turns in the secondary coil (Ns). You're given the number of turns in the primary coil (Np), which is 4000.

Plug these values into the formula:

Np/Ns = 240 V / 12 V

Now, solve for Ns:

Np/Ns = 20

To find Ns, you can rearrange the formula:

Ns = Np / (Np/Ns)

Ns = 4000 / 20

Ns = 200

So, there are 200 turns in the secondary coil.