Question Detail
Question
Four 20-Ω resistors are connected in parallel and the combination is connected to a 20-V emf device. The current in the device is:
Correct Answer
Option C is the correct answer.
Detailed Explanation
When resistors are connected in parallel, the equivalent resistance (R_eq) is calculated as 1/R_eq = 1/R1 + 1/R2 + ... . For four 20-Ω resistors in parallel:1/R_eq = 1/20 + 1/20 + 1/20 + 1/20 = 4/20 = 1/5 Ω^-1.So, R_eq = 5 Ω.According to Ohm's Law, the current (I) is V/R_eq, where V is the voltage. Given V = 20 V:I = 20 V / 5 Ω = 4.0 A.
Hint
First, calculate the equivalent resistance of the parallel combination. Then use Ohm's Law (I = V/R) to find the current.