Question

In a parallel circuit, there are 3 resistors, each with a resistance of 9 Ω. If the total current is 4 A, what is the total voltage?

A. 1.3 V
B. 12 V
C. 36 V
D. 108 V

Answer 1

Following Ohm's Law, you can compute voltage using the formula:


`V=IR`

Where:
V=voltage
I = current
R = Total Resistance

The problem is you do not have total resistance, but that can be computed as well. To get the total resistance in a parallel circuit the formula you need would be:


`(1)/(R_(T)) = (1)/(R_(1))+(1)/(R_(2))+(1)/(R_(3))`

`(1)/(R_(T)) = (1)/(9)+(1)/(9)+(1)/(9)`

`(1)/(R_(T)) = (3)/(9)`

`R_(T)= (9)/(3)`

`R_(T)= 3`

Total resistance is 3Ω

Now that you have your total resistance, you can solve for voltage:


`V=IR`

`V=(4)(3)`

`V=12V`

Voltage is then 12V. The answer is then B.