Question

Calculate by which factor current will changed when doubling the voltage without changing the resistance. Assume ohmic conductor.

• A. decrease by a factor of 4
• B. decrease by a factor of 2
• C. remain unchanged
• D. increase by a factor of 2
• E. increase by a factor of 4

Answer 1

The correct option is D increase by a factor of 2

Let the initial voltage across resistance be $V$ and the resistance be $R$.

$\therefore$ Current through resistor $I=\frac{V}{R}$ (ohm's law)

Now the voltage is doubled i.e $V^{\prime }=2V$

$\therefore$ New current $I^{\prime }=\frac{2V}{R}=2I$

Hence the current increases by a factor of 2.