Two concentric metallic spherical shells A and B of radii a and b respectively (b>a) are arranged such that outer shell is earthed and inner shell is charged to Q. Charge on the outer surface of outer shell will be:
1.
2.
3. -Q
4. zero
The equivalent capacitance across \(A\) and \(B\) in the given figure is:
1. \( \frac{3}{2}C\)
2. \(C\)
3. \( \frac{2}{3}C\)
4. \( \frac{5}{3}C\)
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.
Two capacitors of capacity and are charged to the same potential difference of 6 V. Now they are connected with opposite polarity as shown. After closing switches , their final potential difference becomes:
1. | \(\text{Zero} \) | 2. | \(\frac{4}{3} \mathrm{~V} \) |
3. | \(3 \mathrm{~V} \) | 4. | \(\frac{6}{5} \mathrm{~V}\) |
How many capacitors each of and 250 V are required to form a composite capacitor of and 1 kV?
1. | 16 | 2. | 8 |
3. | 64 | 4. | 32 |
A positive charge q and a negative charge -q are placed at x= -a and x= +a respectively. The variation of V along x-axis is represented by the graph:
1. | 2. | ||
3. | 4. |
Which of the following statements is correct regarding electrostatics of conductors?
1. | The interior of the conductor with no cavity can have no excess charge in the static situation. |
2. | Electrostatic potential is constant throughout the volume of the conductor. |
3. | Electrostatic potential has the same value inside as that on its surface. |
4. | All of these. |
The insulation property of air breaks down at V/m. The maximum charge that can be given to a sphere of diameter 5 m is approximately:
1.
2.
3.
4.
The dielectric constant of pure water is 81. Its permittivity will be: (in MKS units)
1.
2.
3.
4.
In a circuit, 5 C of charge is passed through a battery in a given time. The plates of the battery are maintained at a potential difference of 12 V. The work done by the battery is:
1. | 120 J | 2. | 60 J |
3. | 30 J | 4. | 15 J |