A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power when an ideal power supply of 11 V is connected across it is :

Question

A current of 2 mA was passed through an unknown resistor which dissipated a power of 4.4 W. Dissipated power when an ideal power supply of 11 V is connected across it is : (A)  11 × 10-5 W  (B)  11 × 10-4 W  (C)  11 × 105 W  (D)  11 × 10-3 W

Tardigrade Admin · Accepted Answer

P -I2R 4.4 = 4×10-6R R = 1.1 ×106 Ω P' =(112/R) = (112/1.1) × 10-6 = 11 ×10-5 W

Q. A current of $2 m A$ was passed through an unknown resistor which dissipated a power of $4.4 W$ . Dissipated power when an ideal power supply of $11 V$ is connected across it is :

$11 \times 1 0^{- 5} W$

$11 \times 1 0^{- 4} W$

$11 \times 1 0^{5} W$

$11 \times 1 0^{- 3} W$

$P - I^{2} R$
$4.4 = 4 \times 1 0^{- 6} R$
$R = 1.1 \times 1 0^{6} Ω$
$P^{'} = \frac{1 1 ^{2}}{R} = \frac{1 1 ^{2}}{1.1} \times 1 0^{- 6} = 11 \times 1 0^{- 5} W$

Q. A current of 2mA was passed through an unknown resistor which dissipated a power of 4.4W. Dissipated power when an ideal power supply of 11V is connected across it is :

11×10−5W

11×10−4W

11×105W

11×10−3W