Question

A bulb has been marked as 12V,24W operates a 12V battery for 20 minutes. Calculate the value of current flowing through it?
$\begin{align}
  & A.2A \\
 & B.0.5A \\
 & C.1A \\
 & D.1.5A \\
\end{align}$

Answer 1

Hint: The electric power in watts which is associated with a complete electrical circuit or any other circuital component will be indicating the rate at which energy being converted from the electrical energy of the moving charges to any other form. For example like the heat, mechanical energy, or energy stored in electric fields or magnetic fields. The power can be defined as the product of the applied voltage and the electric current. This will help you in answering this question.

Complete step by step solution:
 The electric power in watts which is associated with a complete electrical circuit or any other circuital component will be indicating the rate at which energy being converted from the electrical energy of the moving charges to any other form. For example like the heat, mechanical energy, or energy stored in electric fields or magnetic fields. The power can be defined as the product of the applied voltage and the electric current. That is we can write that,
$P=VI$
This relation can be rewritten in the form which has been shown below as,
$I=\dfrac{P}{V}$
Therefore, the current flowing through the bulb will be found by substituting the values in this equation. The power of the electric bulb has been given in the question as,
$P=24W$
The voltage of the battery can be mentioned as,
$V=12V$
Substituting these values in the equation can be written as,
$I=\dfrac{24}{12}=2A$

So, the correct answer is “Option A”.

Note: Power is defined as the amount of energy transferred or converted in a unit time. In the International System of Units, the unit of power has been mentioned as watt. In the early books, power is often referred to as the activity. However the power is a scalar quantity.