Question

The current in the wires of a circuit is 60.0 milliAmps. If the voltage impressed across the ends of the circuit were doubled (with no change in its resistance), then its new current would be _____ milliAmps

Answer 1

Answer:

120 mA

Explanation:

The relationship between voltage, current and resistance in a circuit is given by Ohm's law

$I=\frac{V}{R}$

where

I is the current

V is the voltage

R is the resistance

In this problem, we have an initial current of

I = 60 mA

Then the voltage is doubled:

V' = 2 V

while the resistance is kept the same:

R' = R

So the new current is

$I' = \frac{V'}{R'}=\frac{2V}{R}=2\frac{V}{R}=2 I$

so, the current has doubled. Since I = 60 mA, the new current is

$I' = 2(60 mA)=120 mA$