Electric Energy and Power

Question 1: Define Electrical Energy.

Answer:

The energy passed by the electric charges in an electric field is called Electrical Energy, it can either be created by kinetic energy or potential energy of the electric charges.

Question 2: What are the Units of Electrical Energy?

Answer:

Electrical energy is measured in various units which are Joules, kilowatt-hours, electron-volt, etc.

Question 3: What is the Commercial Unit of Electrical Energy?

Answer:

The Commercial Unit of Electrical Energy is kwh or kilo-watthour

Question 4: One unit of electrical energy equals how many joules?

Answer:

One unit of electrical energy is equivalent to 3.6 × 10⁶ joules. It is the commercial unit of electric energy.

Question 5: What are the uses of Electrical Energy?

Answer:

Electrical energy has a variety of uses some of the important uses of electric energy are,

• Electrical energy provides light energy in form of bulbs, LEDs and others.
• Electrical energy provides heat energy in form of heaters and others.
• Electrical energy provides mechanical energy in form of motors and others.

Question 5: Define Electric Power.

Answer:

The electrical energy that is transferred in an electric circuit per unit of time is called electric power, i.e. the rate of electric energy with respect to time is called Electric Power.

Question 6: What is the SI unit of Electric Power?

Answer:

The SI unit for measuring electric power is the Watt.

Question 7: What is the formula for Electric Power?

Answer:

The formula for electric power is given by,

P = VI

where,
V is the potential difference
I is the electric current
P is the electric power

Question 8: Is Electric Power a Scalar or a Vector Quantity?

Answer:

Electric power does not have any direction and hence it is a scalar quantity.

Question 9: How is power expressed using Ohms’s law?

Answer:

The formula of Power explained using Ohm’s law is 

• P =I²R
• P = V²/R

where 
V is the Potential Difference
I is the Electric Current
R is the Resistance
P is the Electric Power

Question 10: Which cells convert Electrical Energy into Chemical Energy?

Answer:

Electrolytic cells are the cells which take electric energy and convert then into chemical energy.

Electric energy is the most important form of energy and is widely used in almost all the electrical devices around us. These devices have a rating written on them. That rating is expressed in Watts and intuitively explains the amount of electricity the device will consume. Bigger devices like AC, refrigerators, etc consume more electricity and thus come with a higher rating.

This rating explains the energy and power consumed by the device. It is very important to get an idea about the ratings and their meaning. Let’s learn about Electrical Energy and Electric Power in detail in this article.