Question

Erg is a unit of:
(A) Energy
(B) Pressure
(C) Force
(D) velocity

Answer 1

Hint Here we find the unit which is called an erg, so the regular metric unit is the Joule in the case of work and also electricity. One Joule is the equivalent of one Newton of force that induces one meter of displacement. In other words, we should realize that the unit of work is the Joule. Then we find that Erg is composed of a unit.
Useful formula:
Relation between joule and erg,
\[\begin{array}{*{20}{l}}
  {1{\text{ }}erg{\text{ }} = \;{{10}^{ - 7}}\;J\; = \;100\;nJ} \\
  {1{\text{ }}erg{\text{ }} = \;{{10}^{ - 10}}\;sn \cdot m\; = \;100\;psn \cdot m\; = \;100\;picosth\`e ne - metres} \\
  {1{\text{ }}erg{\text{ }} = \;624.15\;GeV\; = \;6.2415 \times {{10}^{11}}\;eV} \\
  {1{\text{ }}erg{\text{ }} = \;1\;dyn \cdot cm\; = \;1\;g \cdot c{m^2}/{s^2}}
\end{array}\]

Complete step by step answer
Given by,
We find the unit of Erg
The erg is an energy unit equal to a \[{10^{ - 7}}\;joules\] . It originated in the system of units of the centimeter-gram-second (CGS). It has the Erg symbol. Erg is not a unit of SI. The name derives from ergon,
An erg is the amount of work carried out over a distance of one centimeter with a force of one dyne. It is equal to one-gram centimeter-squared per second-squared \[g = c{m^2}/{s^2}\] in the CGS base units.
Thus, in SI units, it is equivalent to \[{10^7}{\text{ }}joules{\text{ }}or{\text{ }}100{\text{ }}nanojoules{\text{ }}\left( {nJ} \right)\]. An erg is about the amount of work performed typical house fly performing a push up, the leg-bending dip that takes the mouth to the surface on which it stands and backs up.
Lifting a pound of weight requires a foot \[1.356{\text{ }} \times {\text{ }}{10^7}\;\] ergs. The working or energy standard system.
Hence,
Thus, the erg is a unit of energy

Here, option A is the correct answer.



Note The International Method of Energy Measuring Units is Joule. However, energy is often expressed in many other non-SI units, such as ergs, British Thermal Units, calories kilocalories and kilowatt-hours, which when expressed in SI units, require a conversion factor.