Question

PLEASE HELP!! HURRYY

If a step down transformer has 220 V coming into the primary coil of 30 turns and 140 V is coming out of the second coil, how many turns in are in the secondary coil?


a.) 30

b.) 19

c.) 0.05

d.) 7

Answer 1

We can use the formula for the transformer voltage ratio, which states that the ratio of the number of turns in the primary coil to the number of turns in the secondary coil is equal to the ratio of the output voltage to the input voltage:

Np/Ns = Vp/Vs

where Np is the number of turns in the primary coil, Ns is the number of turns in the secondary coil, Vp is the input voltage, and Vs is the output voltage.

We know that Vp = 220 V and Vs = 140 V, and we are trying to find Ns. We also know that Np = 30, since that is the number of turns in the primary coil. Substituting these values into the formula, we get:

30/Ns = 220/140

Simplifying the right side of the equation, we get:

30/Ns = 11/7

Cross-multiplying, we get:

11Ns = 210

Dividing both sides by 11, we get:

Ns = 19

Therefore, the answer is b.) 19.