Question

Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. The total current taken from the supply is :

• A. $2.5A$
• B. $5A$
• C. $7.5A$
• D. $25A$

Answer 1

Answer: (C)

$7.5A$

Power is given as: $P=VI$

For a $60W$ lamp rated for $250V$, the current through is given as: $I=\frac{P}{V}=\frac{250}{100}=2.5A$

Hence, the current flowing through the heater is $2.5A$.

In a parallel circuit, the voltage across each of the components is the same, and the total current is the sum of the currents through each component.
Therefore, when three such heaters are connected in parallel, then the current obtained from the supply is given as $2.5+2.5+2.5=7.5A$