Question

A step-down transformer is used for re-charging the batteries of portable devices such as tape players. The ratio of turns inside the transformer is 10:1, and it is used with 120 V (rms) household service. A particular ideal transformer draws 0.350 A from the house outlet.
A) What are the voltage.
B) What are the current supplied to a tape player from the transformer?
C) How much power is delivered?

Answer 1

Answer with Explanation:

We are given that

$\frac{N_1}{N_2}=10$

$V_1=120 V$

$I_1=0.350 A$

a.$\frac{V_1}{V_2}=\frac{N_1}{N_2}$

Using the formula

$\frac{120}{V_2}=\frac{10}{1}$

$V_2=\frac{120}{10}=12 V$

b.$\frac{I_2}{I_1}=\frac{N_1}{N_2}$

$\frac{I_2}{0.350}=10$

$I_2=0.350\times 10=3.5 A$

c.Power delivered,P=$I_2V_2=I_1V_1$

$P=120\times 0.350=42 W$