Q1 · medium · AI-verified
The capacitance of a spherical conductor of radius 10 cm placed in vacuum is approximately:
- 4.4 pF
- 22.2 pF
- 88.5 pF
- 11.1 pF
Q2 · hard · AI-verified
A parallel plate capacitor with plate area A and separation d is filled with two dielectric slabs of equal thickness d/2 and dielectric constants K₁ and K₂ placed one over the other. What is the equivalent capacitance?
- 2ε₀A(K₁ + K₂) / d
- ε₀A(K₁K₂) / d
- 2ε₀A(K₁K₂) / [d(K₁ + K₂)]
- ε₀A(K₁ + K₂) / (2d)
Q3 · medium · AI-verified
Three capacitors of 2 μF, 3 μF and 6 μF are connected in series. What is the equivalent capacitance?
- 2 μF
- 1 μF
- 3 μF
- 11 μF
Q4 · hard · AI-verified
Two identical metallic spheres A and B carry charges +6Q and −2Q respectively. They are brought into contact and then separated. They are then placed 0.3 m apart. If K = 9×10⁹ N·m²/C², what is the electrostatic force between them?
- 4KQ²/0.09 N (repulsive)
- 8KQ²/0.09 N (repulsive)
- 12KQ²/0.09 N (attractive)
- 2KQ²/0.09 N (attractive)
Q5 · medium · AI-verified
The work done in moving a charge of 5 C from a point at 40 V to a point at 100 V is:
- 700 J
- 200 J
- 300 J
- 500 J