Question

An electric motor takes $5\,A$ from $220\,V$ line. Determine the power of the motor and the energy consumed in $2\,h$ .

Answer 1

To answer this question, we first need to understand what power is.The quantity of energy moved or converted per unit time is referred to as power in physics.The watt, which is equal to one joule per second in the International System of Units, is the unit of power. Power is also referred to as activity in ancient writings. A scalar quantity is power.

Complete step by step answer:
It is given to us in the question that;
Voltage $\left( V \right) = 220V$
Current $\left( I \right) = 5A$
Time $\left( t \right) = 2hrs = 2 \times 60 \times 60 = 7200\sec$
Now, power $\left( P \right)$ is given by the expression;
$P = V \times I$
$\Rightarrow P = 220 \times 5 \\\ \Rightarrow P = 1100W$
Now, we know that energy consumed by the by the motor is given by;
$E = P \times t$
$\Rightarrow E = 1100 \times 7200 \\\ \therefore E = 7.92 \times {10^6}J$

So, we conclude that, power of the motor is $1100{\text{ }}Watt$ . And energy consumed is $7.92 \times {10^6}J$.

Additional information:
Watt: One joule of labor performed per second, or $\dfrac{1}{{746}}$ horsepower, is equal to $1\,watt$ in the International System of Units (SI). The power dissipated in an electrical conductor carrying one ampere current between places with a $1\,volt$ potential difference is called an equivalent. It is named after British engineer and inventor James Watt. One kilowatt is equivalent to $1000\,watts$ . Watts are used to measure the power of most electrical devices.

Note: As power is constantly proportional to the amount of effort done, if a person works at different rates at different times, his power will likewise vary. The concept of average-power enters the picture at this point. The total energy utilised divided by the total time taken is what we call average power. In layman's terms, average power is defined as the average amount of effort or energy converted per unit of time.