Q124 / 200 · NEET 2008 (Screening) · Physics

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

  • A
    $4 \mathrm{~W}$
  • B
    $2 \mathrm{~W}$
  • C
    $1 \mathrm{~W}$
  • Correct answer
    D
    $5 \mathrm{~W}$

Solution

Key Idea : Voltage across $2 \Omega$ is same as voltage across arm containing $1 \Omega$ and $5 \Omega$ resistances. Voltage across $2 \Omega$ resistance, $V=2 \times 3=6 \mathrm{~V}$ So, voltage across lowest arm, $V_1=6 \mathrm{~V}$ Current across $5 \Omega, I=\frac{6}{1+5}=1 \mathrm{~A}$ Thus, power across $5 \Omega$, $P=I^2 R=(1)^2 \times 5=5 \mathrm{~W}$

Hence, the correct answer is option: 'D'.

Relevant Questions