If in the circuit, power dissipation is 150 W , then R is

Question

If in the circuit, power dissipation is 150 W , then R is <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-et8awh9qt0ll.png" /> (A) 2Ω  (B) 6Ω  (C) 5Ω  (D) 4Ω

Tardigrade Admin · Accepted Answer

Power =(V2/R) 150=(V2/R textnet) =( text152/R textnet) (1/R textnet)=(1/R)+(1/2) ∴ R textnet=(2 R/R + 2) ∴ text150 =(( text15)2 (R + 2)/2 R) ∴ R=6Ω

Q. If in the circuit, power dissipation is $150 W$ , then $R$ is

$2Ω$

$6Ω$

$5Ω$

$4Ω$

Power $= \frac{V ^{2}}{R}$
$150 = \frac{V ^{2}}{R _{net}}$
$= \frac{15 ^{2}}{R _{net}}$
$\frac{1}{R _{net}} = \frac{1}{R} + \frac{1}{2}$
$∴ R_{net} = \frac{2 R}{R + 2}$
$∴ 150 = \frac{( 15 ) ^{2} ( R + 2 )}{2 R}$
$∴ R = 6Ω$

Q. If in the circuit, power dissipation is 150W , then R is

2Ω

6Ω

5Ω

4Ω