Electric Energy Formula
Basically energy is ability to do work. When force is applied on an object then object is displace from one position to another. Electric energy is type of kinetic energy or potential energy.
The energy is caused by the movement of charge (electrons) this type of energy is called electric energy. If the electron moves faster then large amount is stored.
Electrical energy can either be created or stored.
Example:
Lightning is example of electrical energy.
The transfer of electrical energy is depend on its power and time taken
So, electric energy = P × t ∵ P = V × I
E = V × I × t
E = V × I × t
E = V I t ∵ V = I R
E = I R I t
E = I2Rt
P = V I t —– (1)
This is required of electric energy.
SI unit of electric energy is Joule (J).
E = Pt
IJ = 1w × 1s
Numericals on Electric Energy Formula:
(1) The current flowing through electric circuit is 3 A and voltage is 12 V. What is electrical power?
Given:
I = 3A
V = 12V
P = V I
P = 12 × 3
P = 36 W.
(2) Consider of flowing circuit.
Calculate the energy spent in 6Ω resistor in 80 sec.
Here two resistors are in series having resistance 6Ω & 3Ω So we have to calculate the equivalent resistance.
Re = R1 + R2
Re = 6 + 3 = 9Ω
We know that the Ohm’s law.
V = IR
I = V/R = 14/9 = 1.55 A
E = V I t
E = I2 R t
= (1.55)2 × 6 × 80
= 2.40 × 6 × 80
E = 1.152 J
Energy spent in 6Ω resistor in 80 sec is 1, 152 J.