Electric Potential and Capacitance

Q1.Which of the following is NOT a property of equipotential surfaces?

• AThey never intersect each other
• BElectric field is perpendicular to them
• CWork done in moving charge along them is zero
• DThey are always planes

Q2.The electrostatic potential energy of a dipole of moment p in uniform field E at angle θ is:

• ApE sinθ
• B-pE cosθ
• CpE cosθ
• D-pE sinθ

Q3.Gauss's law relates electric flux through a closed surface to:

• ATotal charge outside the surface
• BTotal charge enclosed by the surface
• CSurface area of the closed surface
• DShape of the closed surface

Q4.The dielectric strength of air is about 3 × 10⁶ V/m. A parallel plate capacitor with 1 mm air gap can support a maximum voltage of approximately:

• A3 V
• B3000 V
• C300 V
• D30000 V

Q5.The electric potential at a point due to a point charge q at distance r is:

• Akq/r²
• Bkq/r
• Ckq²/r
• Dkq/2r