Question

An electric circuit consists of a variable resistor connected to a source of constant potential difference. If the resistance of the resistor is doubled, the current through the resistor is

Answer 1

Answer:

halved.

Explanation:

Given the following data;

Potential difference = constant

Resistance = 2 * resistance = 2R

To find the current I;

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

$V = IR$

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

Making current (I) the subject of formula, we have;

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

Substituting into the formula, we have;

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

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

$I = \frac {1}{2} * I$

Therefore, if the resistance of the resistor is doubled, the current through the resistor is halved.