Question

When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.

Answer 1

Resistance (R) of a resistor is given by Ohm's law as, V = IR
$R=\frac{V}{I}$
Where, potential difference, V = 12 V
Current in the circuit, $I=2.5mA=2.5\times {10}^{-3}A$
$R=\frac{12}{2.5\times {10}^{-3}}=4.8\times {10}^3\Omega =4.8k\Omega$
Therefore, the resistance of the resistor is $4.8k\Omega$.