MCQ
In the circuit shown below:

The potential difference across the $3 Ω$ resistor is:
  • A
    $\frac{1}{9}\text{V}$
  • B
    $\frac{1}{2}\text{V}$
  • C
    1V
  • D
    2V

Answer

  1. 1V

Explanation:

The resistors of $1 Ω, 2 Ω$ and $3 Ω$ are connected in series. Therefore, the net resistance,

$\text{R} = \text{R}_1 + \text{R}_2 +\text{R}_3$

$\text{R}=1\Omega+2\Omega+3\Omega=6\Omega$

Current in the circuit will be,

$\text{I}=\frac{\text{V}}{\text{R}}$

or $\text{I}=\frac{2}{6}=\frac{1}{3}\text{A}$

Current $=\frac{1}{3}\text{A}$

Therefore, the voltage across the 3I resistor,

V = IR

or $\text{V}=\frac{1}{3}\times3=1\text{V}$

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