Two condensers, one of capacity \(C\) and the other of capacity \(\frac{C}2\) are connected to a \(V\) volt battery, as shown in the figure.
The energy stored in the capacitors when both condensers are fully charged will be:
1. \(2CV^2\)
2. \({1 \over4}CV^2\)
3. \({3 \over4}CV^2\)
4. \({1 \over2}CV^2\)
A parallel plate condenser has a uniform electric field E(V/m) in the space between the plates. If the distance between the plates is d(m) and area of each plate is , the energy (joule) stored in the condenser is:
1.
2.
3.
4.
The energy and capacity of a charged parallel plate capacitor are \(E\) and \(C\) respectively. If a dielectric slab of \(E_r=6\) is inserted in it, then the energy and capacity become:
(Assuming the charge on plates remains constant)
1. | \(6 \mathrm E,~6 \mathrm C\) | 2. | \( \mathrm E,~ \mathrm C\) |
3. | \({E \over 6},~6 \mathrm C\) | 4. | \( \mathrm E,~6 \mathrm C\) |
Surface charge density on the positive plate of a charged parallel plate capacitor is . Energy density in the electric field of the capacitor is:
1.
2.
3.
4.
Five equal capacitors connected in series have a resultant capacitance of . The total energy stored in these when these are connected in parallel and charged to 400 V is:
1. 1 J
2. 8 J
3. 16 J
4. 4 J
A series combination of n1 capacitors, each of value C1, is charged by a source of potential difference 4 V. When another parallel combination of n2 capacitors, each of value C2, is charged by a source of potential difference V, it has the same (total) energy stored in it as the first combination has. The value of C2 in terms of C1 is:
1.
2. 16C1
3. 2C1
4.
A capacitor is charged by a battery. The battery is removed and another identical uncharged capacitor is connected in parallel. The total electrostatic energy of the resulting system:
1. | increases by a factor of 4. |
2. | decreases by a factor of 2. |
3. | remains the same. |
4. | increases by a factor of 2. |
A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected from it. A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect?
1. | The potential difference between the plates decreases K times |
2. | The energy stored in the capacitor decreases K times |
3. | The change in energy stored is \({1 \over 2} CV^{2}(\frac{1}{K}-1)\) |
4. | The charge on the capacitor is not conserved |
Two condensers of capacity 0.3 and 0.6 are connected in series. The combination is connected across a potential of 6 V. The ratio of energies stored by the condensers will be:
1.
2. 2
3.
4. 4
In the circuit shown in figure, energy stored in 6 capacitor will be:
1. | \(48 \times10^{-6}~ \mathrm J\) | 2. | \(32 \times10^{-6}~ \mathrm J\) |
3. | \(96 \times10^{-6}~ \mathrm J\) | 4. | \(24 \times10^{-6}~ \mathrm J\) |