The energy in simple terms can be defined as the capacity for doing work. It can occur in kinetic, potential, electrical, chemical, nuclear, thermal, and various other forms. It is classified as renewable energy and non-renewable energy. Further, in this article, we shall discuss the various units of energy.

## What is the SI Unit of Energy?

*Following is the table of SI unit:*

SI unit |
Joules |

Interestingly, the name of this international unit is kept in honor of James Prescott Joule, a British physicist whose works contributed to the establishment of the energy concept. When we look at the unit in fundamental terms, 1-N.m is equal to 1 Joule and, in terms of SI base units it can be represented as:

\(1\,J=1\,kg(\frac{m}{s})^{2}=1\frac{kg.m^{2}}{s^{2}}\) |

## What is the CGS Unit Of Energy?

*Following is the table of the unit in the CGS system:*

CGS unit |
erg |

The erg is equal to 10^{-7} J. An erg is defined as the amount of the work done by the force of one dyne on one-centimeter distance.

## What is the Unit Of Energy In MKS System?

Following is the table of the unit in the MKS system:

MKS unit |
Joule |

**You may also like to learn more about other concepts related to energy like:**

## Units Of Energy List

Energy units can be preceded by various factors and there are usually different units for measuring energy. Some common units include:

- British thermal unit (BTU)
- Horsepower
- Kilowatt-hour (kWh)
- Calorie
- Electronvolts (eV)
- Hartree (the atomic unit of energy)
- Rydberg units
- Barrel of oil

## Energy Conversion

Following is the table with energy conversion list:

Unit |
Joule |
Calorie |
BTU |
Kilowatt-hour |

Joule |
00 | 0.2390 | 0.000948 | 2.77778E-07 |

Calorie |
4.187 | 00 | 0.00397 | 1.16279E-06 |

BTU |
1055 | 252 | 00 | 0.000293 |

Kilowatt-hour |
3.6E6 | 8.6E5 | 3412 | 00 |

### Commercial Unit of Energy

Kilowatt-hour is the commercial unit of energy.

When large quantities of energy are to be expressed, the SI unit of energy becomes small. Therefore, the commercial unit is used.

## Frequently Asked Questions – FAQs

### What is the relation between power and energy?

The relation between power and energy is that power has units of energy which is divided by time.

The unit of power is Watts.

Unit of energy is Joules

1 Watt = 1 Joule/1 second

### What happens to the unit of energy when the unit of force and length is doubled?

When the unit of force and length is doubled, the unit of unit energy will increase by 4 times.

The relationship between energy, force, and distance is given as:

Energy = force x distance

The units of force and distance are N and m respectively.

Therefore,

E = N x m

Given that,

E = 2 N x 2 m

Therefore, E = 4Nm.

### What is the relation between commercial and SI unit of energy

The commercial unit of energy is 1 kWh. One kilowatt-hour is defined as the amount of energy that is consumed by a device in one working hour at a constant rate of one kilowatt.

The SI unit of energy is Joule.

Therefore, the relationship between commercial and SI unit of energy is:

1 kWh = 1kW x 1h = 1000W x 1h = 1000(J/s) x 3600 s = 3.6 x10^{6} J

### One unit of electrical energy is equal to how many Joules?

One unit of electrical energy is equal to 3.6 × 10^{6} Joules.

### When will a spring have maximum potential energy?

Spring will have maximum energy when it is either pulled out or when it is compressed.

### 1 Joule is equal to how many erg?

1 Joule is equal to 10^{7} ergs.

### Give examples of potential energy.

Following are examples of potential energy:

- Gravitation potential energy
- Elastic potential energy

### List the different forms of kinetic energy.

Following are the different forms of kinetic energy:

- Translational kinetic energy
- Vibrational kinetic energy
- Rotational kinetic energy