Question

The unit for the intensity of electric field is :
A. Newton/Coulomb
B. Volt
C. Joule
D. Newton

Answer 1

Hint: In this question the basic concept of intensity of electric field will be applied that is units of the electric field are newtons per coulomb $\left( {N/C} \right)$, or volts per meter $\left( {V/m} \right)$ . These are derived units where Newton is a unit of force and Coulomb is the unit of charge.
Formula used: Here the formula that is used is $E = \dfrac{F}{q}$ where F= force acting in newtons and q= charge in coulombs.

Complete Step-by-Step solution:
The space around an electric charge in which its influence can be felt is known as the electric field. The electric field intensity at a point is the force experienced by a unit positive charge placed at that point.
$\Rightarrow$ Electric Field Intensity is a vector quantity.
$\Rightarrow$ It is denoted by b ‘E’.
$\Rightarrow$ Formula: Electric Field = F/q
$\Rightarrow$ Unit of E is \[N{C^{ - 1}}\]or $V{m^{ - 1}}$.
The electric field intensity due to positive charge is always directed away from the charge and the intensity due to a negative charge is always directed towards the charge.
Hence , the intensity of electric field at any point is the electric force per unit charge experienced by a test charge placed at that point.
So, intensity of electric field = electric force / charge
The electric force unit is Newton(N) and charge unit is Coulomb (C)
Thus, the unit of intensity of electric field $ = N/C$.

Note: The electric field due to a charge $Q$ at a point in space may be defined as the force that a unit positive charge would experience if placed at that point. The charge $Q$, which is producing the electric field , is called a source charge and the charge $q$, which tests the effect of a source charge, is called a test charge.