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.

• A. 4.8 Ω
• B. 50 Ω
• C. 4800 Ω
• D. 5000 Ω

Answer 1

The correct option is C

4800 Ω

Ohm’s Law states that, V=IR.

V or potential difference = 12V

I = 2.5 mA= 2.5 $\times$ ${10}^{-3}$​ A so R = $\frac{V}{I}$ = $\frac{12}{2.5}$ $\times$ ${10}^3$​ = 4800 $\Omega$