# Confused on amperes in primary & secondary circuits

• kriegera
Remember that the number of turns in the primary and secondary coils are inversely proportional to the voltages and directly proportional to the currents, so using the equations v2/v1=n2/n1 and Ip/Is=Ns/Np will give you the correct solutions for each part.

## Homework Statement

A transformer has 500 turns in its primary coil and 4000 turns in its secondary. (a) What will be the voltage in the secondary if the primary voltage is 110? (b) If 5 amperes flow through the secondary circuit of the transformer, what will the current in the primary be? (c) If there are 8 amperes in the secondary, how many are there in the primary?

I'm a little confused on whether I'm inverting the equation correctly on parts b and c - can someone let me know if this is the formula they use?

## The Attempt at a Solution

v2/v1=n2/n1 So V2/110=4000/500 = 880V

b.)Ip/Is=Ns/Np = Ip/5 = 4000/500 = 40 A

c.)Ip/Is=Ns/Np = Ip/8 = 4000/500 = 64 A

kriegera said:

## Homework Statement

A transformer has 500 turns in its primary coil and 4000 turns in its secondary. (a) What will be the voltage in the secondary if the primary voltage is 110? (b) If 5 amperes flow through the secondary circuit of the transformer, what will the current in the primary be? (c) If there are 8 amperes in the secondary, how many are there in the primary?

I'm a little confused on whether I'm inverting the equation correctly on parts b and c - can someone let me know if this is the formula they use?

## The Attempt at a Solution

v2/v1=n2/n1 So V2/110=4000/500 = 880V

b.)Ip/Is=Ns/Np = Ip/5 = 4000/500 = 40 A

c.)Ip/Is=Ns/Np = Ip/8 = 4000/500 = 64 A

Looks correct to me.