Question

The 250 - turn primary coil of a step‑down transformer is connected to an AC line that is 120.0 V (rms). The secondary coil is to supply 12.0 A (rms) at 9.60 V (rms). Assuming no power loss in the transformer, what is the number of turns N s in the secondary coil? N s = turns What is the rms current i p,rms in the primary coil?

Answer 1

Answer:

Number of turns in secondary is 20

Current in primary is 0.96 A  

Explanation:

We have given number of turns in primary $N_p=250$

Voltage across primary of transformer $V_p=120volt$

Current in secondary coil $i_s=12A$

Voltage across secondary $V_s=9.6volt$

For transformer we know that $\frac{N_p}{N_s}=\frac{V_p}{V_s}$

So $\frac{250}{N_s}=\frac{120}{9.6}$

$N_p=20$

So number of turns in primary is 20

Now $\frac{N_p}{N_s}=\frac{i_s}{i_p}$

$\frac{250}{20}=\frac{12}{i_p}$

$i_p=0.96A$

Current in primary of transformer is 0.96 A