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.

Explanation

V= IR
V =12 V, I = 2.5 mA `implies 2.5xx10^(-3)` A
`12 = 2.5xx10^(-3)xxR`
`R = (12)/(2.5xx10^(-3))= (12xx10^(3))/(2.5) = 4.8 k Omega`