Question

What is the potential difference across the source?
60 V
220 V
440 V
120 V

Answer 1

120 v

Step-by-step explanation:

The two resistors have an equivalent of 20 * 30 /(20+30) = 12 ohms

10 amps of current in the circuit

v = ir

= 10 * 12 = 120 volts

Here is another way:

The two resistors are in prallel so the voltae across both is the same

use the one on the right v = ir = 4 x 30 = 120 v