Question

A current of 9 A flows through an electric device with a resistance of 43 Ω. What must be the applied voltage in this particular circuit?

A. 387 V
B. 4.8 V
C. 387 A
D. 4.8 A

( the answer choice ; "A." 387 V , was marked incorrect. )

Answer 1

Answer: Option (A) is the correct answer.

Step-by-step explanation:

Ohm's law states that current passing through a circuit is directly proportional to the voltage over resistance.

Mathematically,
`I = (V)/(R)`

where, I = current

V = voltage

R = resistance

It is given that electric device has current of 9 A and resistance of 43 ohms. Therefore, calculate the voltage as follows.

`I = (V)/(R)`

or,
`V = I * R`

=
`9 Ampere * 43 (Volts)/(Ampere)`

= 387 V

Thus, we can conclude that the applied voltage in this particular circuit is 387 V.