The volume charge density of a sphere of radius 6 m is 2μC cm-3. The number of lines of force per unit surface area coming out from the surface of the sphere is _______ × 1010 NC-1.
Correct Answer: 45
Solution and Explanation
The number of lines of force per unit surface is nothing but an Electric field at that point
E=ρ\(\frac{r}{3}\)ϵ0, for r=R
E=ρ\(\frac{R}{3}\)ϵ0=2×\(\frac{6}{3}\)×8.85×10-12=0.45×1012 NC-1
=45×1010 N/C
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Concepts Used:
Electrostatic Potential
The electrostatic potential is also known as the electric field potential, electric potential, or potential drop is defined as “The amount of work that is done in order to move a unit charge from a reference point to a specific point inside the field without producing an acceleration.”
SI Unit of Electrostatic Potential:
SI unit of electrostatic potential - volt
Other units - statvolt
Symbol of electrostatic potential - V or φ
Dimensional formula - ML2T3I-1
Electric Potential Formula:
The electric potential energy of the system is given by the following formula:
U = 1/(4πεº) × [q1q2/d]
Where q1 and q2 are the two charges that are separated by the distance d.