Energy - Definition, Types, Difference, FAQs
Have you ever thought about why a Bicycle moves when you press a pedal or why our body feels heat when we sit in the sun? These events occur because of Energy. The fact is that Energy can never be lost, and it is present in various forms. In this article, we will discuss energy in detail to understand the activities happening in everyday life.
This Story also Contains
- What is Energy?
- Sources of Energy
- Energy Conservation Law
- What are the different forms of Energy?
What is Energy?
Energy Definition in Physics: The ability to do any work or cause any changes is called Energy. Energy exists in various forms, such as heat, light, electrical, chemical, and kinetic energy.
Unit of Energy
S.I. unit of energy is Joule (J). Energy is also expressed in many other non-SI system units. Many of these units include calories, ergs, kilowatt-hours, kilocalories, and British Units Thermal.
Examples of Energy
- When you lift a book, you’re using energy to move it.
- The sun provides energy in the form of light and heat, which warms our planet and enables plants to grow.
- Batteries store chemical energy, which powers devices when converted into electrical energy.
Sources of Energy
Sources of energy are the various forms from which we obtain energy in our daily life. These energy sources are classified into various forms:
Renewable energy sources
Energy resources that are present in abundant amounts in nature and won't be extinct are called Renewable energy resources. Some of the examples of Renewable energy sources are - Solar energy, Wind Energy, Hydropower, Biomass, and Geothermal Energy.
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Non-renewable energy sources
These types of energy sources are finite, which means it cannot be replenished easily as they are used up. They are less organic than renewable energy sources. Examples of non-renewable energy sources are- Coal, Nuclear Energy, Natural Gas, and Oil.
Secondary energy sources
Energy resources that do not occur naturally but can be generated from the primary resources available like coal, natural gas, solar, and wind are called Secondary energy sources. Examples of such resources are- Electricity, Refined Fuels like diesel, kerosene, and many others.
Energy Conservation Law
According to Law of Conservation of Energy- "An energy can neither be created nor destroyed, it can only transformed from one form to another." The total amount of energy in a closed system remains constant over time.
What are the different forms of Energy?
There are many different types of energy, which fall into two main categories: Potential energy and Kinetic energy. Let's look at the different types of energy and their respective examples.
Mechanical Energy
The mechanical energy $(M E)$ of an object is given by:
$$
M E=K E+P E
$$
where:
- $K E=$ Kinetic Energy, calculated as $\frac{1}{2} m v^2$,
- $P E=$ Potential Energy, calculated as $m g h$ (for gravitational potential energy),
Kinetic Energy
Kinetic force can be defined as the force of motion. When an object is in a state of motion, it is said to have kinetic energy. For example, running water, a moving ball, and more.
The formula to calculate Kinetic energy is:
$$
K E=\frac{1}{2} m v^2
$$
where:
- $m=$ Mass of the object (in kilograms, kg),
- $v=$ Velocity of the object (in meters per second, $\mathrm{m} / \mathrm{s}$ ).
Chemical Energy
Energy is stored in the bonds of chemical compounds, such as molecules and atoms are called as Chemical Energy. Chemical energy is a form of potential energy because it depends on the position and arrangement of atoms within molecules. Once the chemical energy is released from an object, it is usually converted into something completely new.
Light energy
Light energy is a type of electrical radiation. Light contains photons produced when the atoms of an object heat up. Light travels in waves and is the only source of energy visible to the human eye.
Light is made up of photons, which are small packets of energy. When the atomic matter is heated, photons are produced by the movement of atoms. Photons are produced according to the temperature of an object.
Heat Energy
Heat energy can also be called thermal energy, which is produced when rising temperatures cause molecules and atoms to move faster and more precisely. Examples of hot energy are heat from the sun, a cup of hot chocolate, baking in the oven, and heat from a heater.
Frequently Asked Questions (FAQs)
Gravity is stored at the height of an object
e.g. high gravity is stored on heavy and elevated objects. When someone climbs into a cliff and picks up speed, the force of gravity turns to the force of motion. Hydropower is another example of gravity, in which gravity forces water down a propeller to provide electricity.
Motion power is stored within the flow of objects. As soon as they go, a lot of energy is saved. It takes energy to persuade a moving object, and energy is released when the object is slow-moving. The wind is an example of the power of movement. A striking example of the force of movement can be a car collision - The car puts on a complete stop and releases all its movement power without delay in an uncontrolled moment.
According to the law of conservation, "Energy is not created, or destroyed, but can be changed from one form to another."
The energy we use is simply the conversion of other species. It has no specific sources. However, most of the energy we have used is the result of the Sun.
Looking at the representation above, it is clear that we need power. We get this energy from eating food, which is also derived from plants and animals. In fact, all animals, plants, fungi, viruses, bacteria, and other organisms need the energy to do all they can.
Other sources of renewable energy are solar energy, wind power, biomass and hydropower. It is called renewable because it is continuous. It is also called another form of energy as these are other forms of renewable energy.
Gravity is stored at the height of an object
e.g. high gravity is stored on heavy and elevated objects. When someone climbs into a cliff and picks up speed, the force of gravity turns to the force of motion. Hydropower is another example of gravity, in which gravity forces water down a propeller to provide electricity.
According to the law of conservation, "Energy is not created, or destroyed, but can be changed from one form to another."
The energy we use is simply the conversion of other species. It has no specific sources. However, most of the energy we have used is the result of the Sun.
Looking at the representation above, it is clear that we need power. We get this energy from eating food, which is also derived from plants and animals. In fact, all animals, plants, fungi, viruses, bacteria, and other organisms need the energy to do all they can.
Other sources of renewable energy are solar energy, wind power, biomass and hydropower. It is called renewable because it is continuous. It is also called another form of energy as these are other forms of renewable energy.
Questions related to
On Question asked by student community
1.NIT Calicut overall highest package in recent year was fifty one lakh rupees
2. Overall average package was around twelve to thirteen lakh rupees
3. For BTech students average package for energy branch is close to overall average
4. Placements for BTech courses was reported at eighty five percent in past year
5. Top 100 plus companies visit for campus recruitment
6. Energy branch seat intake is limited to around forty students per year
7. Energy branch students often get offers similar to core engineering branches
8. Placements depend on academic record and branch popularity
https://www.careers360.com/university/national-institute-of-technology-calicut/placement
https://engineering.careers360.com/articles/jee-main-cutoff-for-nit-calicut
Hello Amit Kumar,
As a working professional managing operations and maintenance of EV charging stations, both programs - the Online MBA in Operations Management or the PGDM in Energy Management from Symbiosis - can be valuable, but the most appropriate choice will depend on your long term career goals.
- The Online MBA in Operations Management would build on your foundational knowledge base in process optimization, logistics and strategic operations which is core to expanding the EV sector infrastructure and optimizing your maintenance workflows.
- While the PGDM in Energy Management from Symbiosis is narrower in focus and leads more deeply into the energy sector, it provides an advantage, particularly for someone wanting to take a stronger focus on sustainability, energy policy and the power sector dynamics that influence these areas.
If you hope to become a strategic leader in the EV and energy sectors, the PGDM in Energy Management fits more closely with this purpose. If you hope to assume broader leadership roles in diverse industries, then an MBA in Operations gives you broader flexibility.
Hello Sukhada,
Here's the list of few colleges offering B.tech/B.E. in sustainableenergy/renewableenergy :
- JLU School of Engineering and Technology, Bhopal
- RGIPT Amethi - Rajiv Gandhi Institute of Petroleum Technology, Amethi
- Sanjay Ghodawat University, Kolhapur
- Sarala Birla University, Ranchi
- Sharda University, Greater Noida
For more colleges and more detailed information you may visit career360: https://engineering.careers360.com/colleges/list-of-be-btech-in-renewable-energy-colleges-in-india
Thank you!!
Energy engineering, as a field, is rapidly gaining traction both in India and on the global stage. Career prospects and compensation in this domain are, to a significant extent, determined by several factors—chief among them being the reputation of one’s alma mater, technical proficiency, relevant internship or research experience, and adaptability to various industry roles.
Graduates from premier institutions such as IIT Bombay, IIT Delhi, or IIT Kharagpur often secure lucrative job offers, with top packages reaching approximately Rs20–30 lakh per annum. Notably, multinational corporations like Schlumberger, Shell, ExxonMobil, and even technology firms such as Google have recruited from these cohorts. International opportunities, particularly in regions like Europe or the United States, can yield offers exceeding Rs50 lakh per annum for select candidates in consulting or research roles.
Key recruiters in the Indian context include Reliance, Adani Green, Tata Power, Siemens, BHEL, Indian Oil, L&T Energy, Bosch, NTPC, GE, and ReNew Power, among others. These organizations are actively engaged in hiring talent with a strong foundation in energy systems.
For context, the average compensation figures are as follows:
- IITs: Rs10–18 lakh per annum
- NITs: Rs6–10 lakh per annum
- Private colleges: Rs3–6 lakh per annum
- MS abroad: Rs30–60 lakh per annum (international placements)
It is essential for aspirants to cultivate proficiency in industry-standard software tools such as MATLAB, ANSYS, AutoCAD, HOMER, EnergyPlus, and PVsyst. In-depth knowledge of renewable energy systems—solar, wind, and hybrid configurations—is also highly advantageous. Internships with public sector undertakings or startups in the energy domain can further bolster one’s profile. Moreover, developing robust analytical and programming abilities (Python, R, simulation tools) is increasingly important, given current industry requirements.
Pursuing advanced degrees such as an M.Tech or MS abroad can significantly enhance one’s career trajectory and earning potential.
In summary, for individuals genuinely committed to the sector and diligent in skill development, energy engineering offers substantial opportunities for growth, particularly in the context of global trends toward renewable energy and carbon neutrality. For more granular information—such as placement statistics by institution or guidance on career planning—further assistance is available upon request.
Hello aspirant,
Here below I am providing you with the name of some of the colleges you can look for:
- The Indian Institute of Technology Bombay
- The Indian Institute of Technology Delhi
- National Institute of Technology Kurukshetra
- Amity University, Noida
- K. J. Somaiya College of Engineering
Thank you
Hope this information helps you