Question

The resistance of a resistor is kept constant and the potential difference across it’s ends is

decreased to half of its former value. State the change that will occur in the current flowing

through it.

​

Answer 1

Initially, let the current flowing through the resistor be I ampere, it's resistance be R ohm, potential difference across its ends be V volt.

Then, by Ohm's law, V=IR => I = V/R

Now, Resistance of the resistor = R (kept constant)

Potential difference across its ends = V - (1/2×V)

I = V/R = (V-0.5V)/R = 0.5V/R = 0.5 × V/R

So, the current flowing through it will become 0.5 times of its initial value. In other words, Current will be half of its former value.