Question

If the voltage impressed across a circuit is held constant while the resistance doubles, what change occurs in the current?

Answer 1

Answer:

The current halves

Explanation:

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

$V=RI$

where

V is the voltage

R is the resistance

I is the current

We can rewrite the formula as

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

we see that I is directly proportional to V and inversely proportional to R.  In this problem, V is held constant while R is doubled:

$R'=2R$

so, the new current in the circuit will be

$I'=\frac{V}{R'}=\frac{V}{2R}=\frac{1}{2}I$

So, the current halves.