You are traveling in a car during a thunderstorm. In order to protect yourself from lightning, you would prefer to
(1) Touch the nearest electric pole
(2) Take shelter under a tree
(3) Get out and crouch on the ground
(4) Remain in the car
Capacitors are connected in series across a source of emf 20KV. The potential difference across will be
(1) 5 KV
(2) 15 KV
(3) 10 KV
(4) 20 KV
Two metallic spheres of radii 2cm and 3cm are given charges 6mC and 4mC respectively. The final charge on the smaller sphere will be if they are connected by a conducting wire
(1) 4mC
(2) 6mC
(3) 5mC
(4) 10mC
1. | \(v\) | 2. | \(v \over \sqrt{2}\) |
3. | \(v \sqrt{2}\) | 4. | \(2v\) |
In the circuit shown in figure, energy stored in \(6~\mu\text{F}\) capacitor will be:
1. | \(48 \times10^{-6}~\text{J}\) | 2. | \(32 \times10^{-6}~\text{J}\) |
3. | \(96 \times10^{-6}~\text{J}\) | 4. | \(24 \times10^{-6}~\text{J}\) |
An air capacitor of capacity is connected to a constant voltage battery of 12 V. Now the space between the plates is filled with a liquid of dielectric constant 5. The charge that flows now from battery to the capacitor is
1. 120
2. 699
3. 480
4. 24
Two identical metal plates are given charges respectively. If they are now brought close to form a parallel plate capacitor with capacitance , the potential difference between them is :
1.
2.
3.
4.
A and B are two concentric metallic shells. If A is positively charged and B is earthed, then electric
1. Field at common centre is non-zero
2. Field outside B is nonzero
3. Potential outside B is positive
4. Potential at common centre is positive
The electric potential at a point at distance 'r' from a short dipole is proportional to
(1)
(2)
(3)
(4)
The capacitance of a parallel plate capacitor is C. If a dielectric slab of thickness equal to one-fourth of the plate separation and dielectric constant K is inserted between the plates, then new capacitance become
1.
2.
3.
4.