Question

The power dissipated in 3 resistor in the circuits as shown in the figure is 2 W. The power dissipated in 7 resistor will be:​

Answer 1

Answer:

Use formula

P=V2 / R

Answer 2

Given:

The power dissipated in 3-ohm resistor is 2 W

To Find:

The power dissipated in a 7-ohm resistor

Solution:

The formula for power is

$P=I^{2}\times R$

Power for $3 \Omega$ resistor

$\\P_{3\Omega}=(\frac{I}{2})^{2} \times3\\2=\dfrac{I^{2} }{4}\times3 \\\dfrac{I^{2}}{4} =\dfrac{2}{3}$

Power for $7\Omega$ resistor

$P_{7\Omega}=I^{2}\times R\\=(\frac{I}{2})^{2}\times7\\=\frac{I^{2} }{4}\times7\\ =(\frac{2}{3} ) \times7\\=\frac{14}{3} W$

The power dissipated in 7 Ω resistor is $\dfrac{14}{3}\W.$