By using Coulomb's law,define unit charge.

Vedclass pdf generator app on play store
Vedclass iOS app on app store
(N/A) In $SI$ units,the unit of charge is the Coulomb $(C)$.
According to Coulomb's law,the force between two point charges is given by $F = k \frac{q_1 q_2}{r^2}$,where $k = \frac{1}{4 \pi \epsilon_0} \approx 9 \times 10^9 \ N \cdot m^2/C^2$.
If we set $q_1 = q_2 = 1 \ C$ and $r = 1 \ m$,the force becomes $F = (9 \times 10^9) \times \frac{1 \times 1}{1^2} = 9 \times 10^9 \ N$.
Definition: $1 \ C$ is defined as the magnitude of charge that,when placed at a distance of $1 \ m$ from an identical charge in a vacuum,experiences an electrostatic repulsive force of $9 \times 10^9 \ N$.

Explore More

Similar Questions

$A$ certain charge $2Q$ is divided at first into two parts $q_{1}$ and $q_{2}$. Later,the charges are placed at a certain distance. If the force of interaction between the two charges is maximum,then find the value of $\frac{Q}{q_{1}}$.

How did Coulomb determine the law of electric force between two point charges?

Difficult
View Solution

Equal charges $q$ are placed at the four corners $A, B, C, D$ of a square of side length $a$. The magnitude of the net electrostatic force on the charge at $B$ is:

Difficult
View Solution

Two point charges $A$ and $B$ with magnitudes $+4q$ and $-4q$ are placed along a line separated by a distance $r$. The force acting between them is $F$. If $25\%$ of the charge from point $A$ is transferred to point $B$,the force between the charges now becomes:

Two identically charged pith balls are suspended from the same point by two massless identical threads. The density of each ball is $\rho$. If the system is immersed in a medium of density $\sigma$ and the balls remain at the same angle of deflection,then the dielectric constant of the medium is:

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo