Four 20-$\Omega$ resistors are connected in series and the combination is connected to a 20-V emf device.The potential difference across any one of the resistors is:
A)1 V
B)4 V
C)5 V
D)20 V
E)80 V

Question

Quizplus · Accepted Answer

Since the resistors are connected in series, the total resistance is R = 4 * (20 Ω) = 80 Ω. 
Using Ohm's Law, V = IR, the current through the circuit is I = V/R = 20 V/80 Ω = 0.25 A. 
Since the resistors are in series, the potential difference across each resistor is proportional to its resistance. 
Therefore, the potential difference across each resistor is V = IR = (0.25 A)(20 Ω) = 5 V. 
Thus, the correct answer is C.

Four 20- Ω\OmegaΩ Resistors Are Connected in Series and the Combination Is Connected

Four 20- $\Omega$ Resistors Are Connected in Series and the Combination Is Connected