Mention the $MKS$ and $CGS$ units of work,define them,and write the dimensional formula of work.

(N/A) The $MKS$ unit of work is the Joule $(J)$.
Definition of Joule: One Joule of work is said to be done when a force of $1 \text{ Newton}$ displaces a body by $1 \text{ metre}$ in the direction of the applied force.
$1 \text{ Joule} = 1 \text{ N} \cdot \text{m} = 1 \text{ kg} \cdot \text{m}^2 \cdot \text{s}^{-2}$.
The $CGS$ unit of work is the erg.
Definition of erg: One erg of work is said to be done when a force of $1 \text{ dyne}$ displaces a body by $1 \text{ cm}$ in the direction of the applied force.
$1 \text{ erg} = 1 \text{ dyne} \cdot \text{cm} = 1 \text{ g} \cdot \text{cm}^2 \cdot \text{s}^{-2}$.
Dimensional formula of work: $[M^1 L^2 T^{-2}]$.
Conversion: $1 \text{ Joule} = 10^7 \text{ erg}$.
Practical units of work/energy:

erg	$10^{-7} \text{ J}$
Electron volt (eV)	$1.6 \times 10^{-19} \text{ J}$
Calorie (cal)	$4.186 \text{ J}$
Kilowatt hour (kWh)	$3.6 \times 10^6 \text{ J}$