Question

A current of $3\text{A}$ flows through the $2\Omega$ resistor shown in the circuit. The power dissipated in the $5\Omega$ resistor is


​​​​​​​$[$1 Mark$]$

• A. $1\text{W}$
• B. $5\text{W}$
• C. $4\text{W}$
• D. $2\text{W}$

Answer 1

The correct option is B $5\text{W}$

Given:-
Current through $2\Omega$ resistor $=3\text{A}$
So, Potential difference across $2\Omega$ resistor
$V=IR=3\times 2=6\text{V}$

As in parallel connection, potential difference is same

The potential difference across $1\Omega$ and $5\Omega$ series combination is $6\text{V}$

$\therefore$ Current through $1\Omega$ and $5\Omega$ resistor

$I=\frac{V}{R_S}$

$I=\frac{6}{1+5}$

$I=1\text{A}$

Power dissipated in $5\Omega$ resistor, $P=I^{2}R$

$P=(1{)}^2\times 5$

$P=5\text{W}$