AP EAMCET2016PhysicsElectrostatics
The figure shows equipotential surfaces concentric at O . The magnitude of electric field at a distance r metres from O is
Options
- A9 r^2 Vm ⁻¹
- B16 r^2 Vm ⁻¹
- C2 r^2 Vm ⁻¹
- D6 r^2 Vm ⁻¹
Correct answer
D. 6 r^2 Vm ⁻¹
Step-by-step solution
Potential v= k q r For 30 ~V equipotential surface, aligned & 30= k q t , here r=20 ~cm =20 10⁻² ~m & 30= k q 20 10⁻² & kq =60 10 10⁻²=6 aligned Therefore, electric field at distance r from charge q . E = k q r^2 = 6 r^2 ~V ⁻¹