Four 20-$\Omega$ resistors are connected in parallel and the combination is connected to a 20-V emf device.The current in the device is:
A)0.25 A
B)1.0 A
C)4.0 A
D)5.0 A
E)100 A

Question

Quizplus · Accepted Answer

When resistors are connected in parallel, the total resistance $ R_t $ is given by $ \frac{1}{R_t} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \frac{1}{R_4} $. For four 20 $\Omega$ resistors, $ R_t = \frac{20}{4} = 5 \Omega $. Using Ohm's law $ V = IR $, the current $ I $ is $ \frac{20V}{5\Omega} = 4.0 A $.

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

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