Question

The potential difference between the terminals of an electric heater is $60\text{V}$ and draws a current of $4\text{A}$ from the source. What current the heater will draw if the potential difference is increased to $90\text{V}?$

• A. $4\text{A}$
• B. $5\text{A}$
• C. $6\text{A}$
• D. $7\text{A}$

Answer 1

The correct option is C $6\text{A}$

We know that, from Ohm's law,

$V=IR$

For same resistor, $V\propto I$

$\Rightarrow \frac{V_1}{I_1}=\frac{V_2}{I_2}$

$\Rightarrow \frac{60}{4}=\frac{90}{I_2}$

$\Rightarrow I_2=6\text{A}$