Question

Establish a relation between an electron volt and the SI unit of the physical quantity which it measures.

Answer 1

Heya friend!!
Rajdeep here...

Electron volt (eV) is an unit which measures Energy.
1eV is the energy gained by an electron when it is accelerated through a potential difference of 1V (1 Volt).

Si unit of Energy is Joule.
So relation between Electron Volt and Joule is:

1eV = $1.6$ × $10^{-19}$J

Hope my answer is satisfactory!!
Thanks...