Four resistors having resistances of $20 \Omega , 40 \Omega , 60 \Omega$, and $80 \Omega$ are connected in series across an ideal dc voltage source. If the current through this circuit is $0.50 \mathrm {~A}$, what is the voltage of the voltage source?
A) $100 \mathrm {~V}$
B) $60 \mathrm {~V}$
C) $40 \mathrm {~V}$
D) $80 \mathrm {~V}$
E) $20 \mathrm {~V}$

Question

Quizplus · Accepted Answer

The total resistance in series is the sum of all resistances: $20 \Omega + 40 \Omega + 60 \Omega + 80 \Omega = 200 \Omega$. Using Ohm's law $V = IR$, where $I = 0.50 A$ and $R = 200 \Omega$, the voltage $V = 0.50 A \times 200 \Omega = 100 V$.

Four Resistors Having Resistances Of 20Ω,40Ω,60Ω20 \Omega , 40 \Omega , 60 \Omega20Ω,40Ω,60Ω

Four Resistors Having Resistances Of $20 \Omega , 40 \Omega , 60 \Omega$