Question

A geyser has a rating of $2 KVA$, $240 V$. What is the electrical energy consumed by it in KWh and in joule if it is used for $90$ mins?

Answer 1

Power and voltage are given in the question. We have to find the electrical energy for a given time period in KWh and in joule. First, we will find energy in KWh by multiplying power and time in hours. Then, by the relation between KWh and joule. We will convert KWh into joules.

Complete step-by-step solution:
Given: Rating = $2 KVA$
Voltage, $V = 240 V$
Time, $t = 90 mins$
First, we convert minutes into hours.
$t = \dfrac{90}{60} = \dfrac{3}{2}h$
Power, $P = 2KW = 2 \times 10^{3} W$
Energy is equal to the product of power and time.
Energy, $E = P \times t$
$E = 2 \times 10^{3} \times \dfrac{3}{2}$
$E = 3 \times 10^{3} Wh$
$E = 3KWh$
Now, we will convert KWh into joules.
$1KWh = 3.6 \times 10^{6} J$
$E = 3 \times 3.6 \times 10^{6} J$
$E = 10.8 \times 10^{6} J$
The electrical energy consumed by it in KWh is $3 KWh$ and in joule is $10.8 \times 10^{6} J$.

Note: Electrical energy is the energy obtained as a result of the movement of electrons. When utilized loosely, electrical energy is defined as the energy that has been transformed from electrical potential energy. This energy is provided by the union of electric current and electric potential delivered by an electrical circuit. When this electric potential energy has been transformed into another type of energy, it stops being electric potential energy. Thus, all electrical energy is potential power before it is given to the end-user. Once changed from potential energy, electrical energy can constantly be named different energy types (heat, light, motion, etc.).