Question
17. A 20.-ohm resistor has 40 coulombs passing through it in 5.0 seconds The potential difference across the resistor is A) 8.0 V B) 100V C) 16 ov D) 200 V
Answer
4.4
(270 Votes)
Norma
Veteran · Tutor for 9 years
Answer
A
Explanation
This question is about Ohm's law which states that the current through a conductor between two points is directly proportional to the voltage across the two points. The law is usually expressed by the formula V=IR where I is the current in amps, V is the potential difference in volts and R is resistance in ohms. From the question, R =20Ω, and I=Q/t where Q is quantity of charge and t is time, so I=40C/5.0sts]=8.0A. Then substitute R and I into the voltage formula V=IR, we get V=8.0A*20Ω.