What is Energy
Energy is nothing but the ability to do work; there are several forms of energy on this planet. In physics, the Energy is considered a property that can be measured, which can be further transformed from one form to another to achieve a certain kind of work. Energy is measured in joules as per the International System of Units,. Energy is also measured in other units, such as calories, ergs, etc.
The law of energy conservation, which has been an important law as far as the study of energy and its forms are concerned, states that “The energy can only be transformed from one form to another. It cannot be created and can’t be destroyed either”. Joule is the SI unit of energy.
Since, there are various forms of Energy, but fundamentally it is classified into two types that is:
- Kinetic Energy
- Potential Energy
And rest of the other forms of energy like chemical energy, thermal energy, solar energy, sound energy, wind energy, hydroelectric energy, nuclear energy, etc. are just the branches of these two fundamental forms of energies.
Important Questions on Forms of Energy
1) The heat trapped inside the Earth is called_____
a) Thermal energy
b) Potential energy
c) Geothermal energy
d) Nuclear energy
Correct Option: (c)
Explanation: Geothermal energy is a clean and sustainable energy that is trapped inside the earth.
2) Energy is released from fossil fuels when they are_____
a) Cooled
b) Transformed
c) Burned
d) Pumped
Answer: (c)
Explanation: Fossil fuels release heat energy when they are burned, that is why they are called fuels. Billions of years ago, fossil fuels were formed from the remains of living organisms. Natural gas and coal are some examples of fossil fuels.
3) Energy is a_____
a) point function
b) property of the system
c) extensive property
d) all of the mentioned
Correct Option: (d)
Explanation: For every state of the system energy has a fixed value.
4) Which among the following is not a type of primary resource?
a) Sunlight
b) Coal
c) Hydrogen Energy
d) Crude oil
Correct Option: (c)
Explanation: Since, hydrogen energy is mainly obtained from fossil fuels which are primary sources of energy, it is considered as a secondary source of energy because. Crude oil, coal, and sunlight are the primary source of energy because they can be directly obtained from nature.
5) When the energy received by a system and the energy spent by the system are divided, to obtain the raw energy source then it is known as?
a) Efficiency
b) Power ratio
c) Energy ratio
d) Energy yield ratio
Correct Option: (d)
Explanation: When the energy received by a system and the energy spent by the system are divided, to obtain the raw energy source then it is known as energy yield ratio.
6) In hydroelectricity power_____
a) Kinetic energy is converted into potential
b) Potential energy is converted into kinetic energy
c) Wind energy is converted into solar energy
d) Solar energy is converted into wind energy
Correct Option: (b)
Explanation: The kinetic energy of the moving water is used by the hydroelectricity power stations. But the water comes from the storage area that comes behind the dam built at a height across a river valley, due to which the potential energy is stored in the water. This is the reason why potential energy is transformed into kinetic energy.
7) Which form of energy is used in the production of wave energy?
a) Wind energy
b) Kinetic energy
c) Electrical energy
d) Thermal energy
Correct Option: (b)
Explanation: Due to the waves present on the surface, the water in the sea rises and falls. To drive electricity generators kinetic energy of this movement is used by wave machines. Wave energy is fundamentally the power drawn from waves and it is also known as ocean energy.
8) Fire is a form of_____
a) Solar energy
b) Thermal energy
c) Cosmic energy
d) Potential energy
Correct Option: (b)
Explanation: Fire is a form of thermal energy because thermal energy is the result of the transmission of temperature of an object in the form of heat from a source of greater temperature to a source of lower temperature by modes such as conduction, convection or radiation.
9) Which of the following quantities will not change for a free-falling body?
a) Total potential energy
b) Total kinetic energy
c) Total mechanical energy
d) Heat energy
Correct Option: (c)
Explanation: The velocity of a body is falling freely under the influence of gravity, increasing as height decreases. Hence, the kinetic energy increases and the potential energy decreases. But, as per the law of conservation of energy the total mechanical energy, which is the sum of kinetic and potential energy always remains constant.
10) Based on usability, the classification of energy sources can be done as_____
a) Primary, tertiary resources
b) Primary, secondary, tertiary resources
c) Primary, intermediate and secondary resources
d) None of these
Correct Option: (c)
Explanation: Based on the purpose or usability, the energy resources are classified into primary, intermediate and secondary resources. Primary sources are already present in nature, after the stages of transformation, we can obtain intermediate resources from primary resources. And finally, the energy supplied to the consumer is the tertiary source of energy.
Practise Questions
1) What is the law of conservation of energy?
2) Define nuclear energy.
3) What is kinetic energy?
4) What is potential energy?
5) What is the unit of energy?
|
Related Articles |
|---|
Suggested Videos
Stay tuned to BYJU’S and Fall in Love with Learning!
