How many turns are in its secondary coil, if its input voltage is 120 V and the primary coil has 210 turns

Complete Question

How many turns are in its secondary coil, if its input voltage is 120 V and the primary coil has 210 turns.

The output from the secondary coil is  12 V

The value  is  

Explanation:

From the equation we are told that

   The input voltage is  

   The number of turns of the primary coil is

    The output from the secondary is

From the transformer equation

Here is the number of turns in the secondary coil

=>

=>

=>

when a device is used in a circuit in which the voltage is 81 v, the current flowing through the device is 3 a. what is the resistance of the device?

a. 27 ω

b. 40.5 a

c. 243 ω

d. 243 a

the correct answer is a. 27