A 100 μF capacitor is charged to a potential difference of 50 V, the charging battery then being disconnected. The capacitor is then connected to a second capacitor. If the measured potential difference drops to 35 V, the capacitance of the second capacitor is
52 μF
37 μF
59 μF
43 μF
When air is repalced by a dielectric medium of constant K, the maximum force of attraction between two charges, separated by a distance.
decreases K times
increases K times
remains unchanged
becomes 1/K2 times
The dielectric strength of air at NTP is 3 × 106 V/m. The maximum charge that can be given to a spherical conductor of radius 3 m is
3 × 104 C
3 × 10-3 C
3 × 10-2 C
3 × 10-1 C
The dielectric strength of air at NTP is 3 x 106 V/m. The maximum charge that can be given to a spherical conductor of radius 3 m is
3 x 104 C
3 x 10-3 C
3 x 10-2 C
3 x 10-1 C
The formation of a dipoleis due to two equal and dissimilar point charges placed at a
short distance
long distance
above each other
none of the above
If the potential of a capacitor having capacity 6μF is increased from 10V to 20 V, then increase in its energy will be
4 x 10-4 J
4 x 10-14 J
9 x 10-4 J
12 x 10-6 J
The work done in carrying a charge Q once round the circle of radius r with charge Q at the centre of the circle is
zero
A capacitor connected to a 10 V battery collects a charge of 40 μC with air as dielectric, and 100 μC with oil as dielectric. The dielectric constant of oil is
4
8
2.5
1.5
A point Q lies on the perpendicular bisector of an electric dipole of dipole moment p. If the distance of Q from the dipole is r, (much larger than the size of the dipole) then electric field at Q is proportional to
p-1 and r2
p and r-2
p2 and r-3
p and r-3
