An ideal 100-V dc battery is applied across a series combination of four resistors having resistances of 20 Ω,40 Ω,60 Ω,and 80 Ω.What is the potential difference across the 40-Ω resistor?
A)20 V
B)40 V
C)60 V
D)80 V
E)100 V

Question

Quizplus · Accepted Answer

The total resistance in the series circuit is 20 Ω + 40 Ω + 60 Ω + 80 Ω = 200 Ω. The total current (I) through the circuit is given by Ohm's Law, I = V/R = 100 V / 200 Ω = 0.5 A. The potential difference (V) across the 40-Ω resistor is then found by V = IR = 0.5 A * 40 Ω = 20 V.

An Ideal 100-V Dc Battery Is Applied Across a Series