railway RRB JE (CBT I + CBT II) Mock Test 2024 Electromagnetic Theory Electrostatics Electrostatic Field
For a point charge having electric flux density, \(D=\frac{Q}{4\pi {{r}^{2}}}{{a}_{r}},\) where ar is the unit vector in radial direction; volume charge density ρv is:
1
1
2
0
3
Infinite
4
\(\frac{Q}{4\pi }\)