If a charged spherical conductor of radius 10 cm has potential V at a point distant 5 cm from its centre, then the potential at a point distant 15 cm from the centre will be -
(1)
(2)
(3)
(4) 3 V
The ratio of momenta of an electron and an -particle which are accelerated from rest by a potential difference of 100 volt is
(1) 1
(2)
(3)
(4)
Ten electrons are equally spaced and fixed around a circle of radius R. Relative to V = 0 at infinity, the electrostatic potential V and the electric field E at the centre C are:
1. | \(V \neq 0 \text { and } \vec{E} \neq 0\) |
2. | \(V \neq 0 \text { and } \vec{E}=0\) |
3. | \(V=0 \text { and } \vec{E}=0\) |
4. | \(V=0 \text { and } \vec{E} \neq 0\) |
A proton is about 1840 times heavier than an electron. When it is accelerated by a potential difference of 1 kV, its kinetic energy will be -
(1) 1840 keV
(2) 1/1840 keV
(3) 1 keV
(4) 920 keV
As per this diagram a point charge +q is placed at the origin O. Work done in taking another point charge –Q from the point A [co-ordinates (0, a)] to another point B [co-ordinates (a, 0)] along the straight path AB is
(1) Zero
(2)
(3)
(4)
The capacity of a condenser is 4 × 10–6 farad and its potential is 100 volts. The energy released on discharging it fully will be -
(1) 0.02 Joule
(2) 0.04 Joule
(3) 0.025 Joule
(4) 0.05 Joule
The energy stored in a condenser of capacity C which has been raised to a potential V is given by -
(1)
(2)
(3) CV
(4)
Eight drops of mercury of equal radii possessing equal charges combine to form a big drop. Then the capacitance of bigger drop compared to each individual small drop is
(1) 8 times
(2) 4 times
(3) 2 times
(4) 32 times
The capacity of a parallel plate condenser is C. It's capacity when the separation between the plates is halved will be?
(1) 4 C
(2) 2 C
(3)
(4)
If the dielectric constant and dielectric strength be denoted by k and x respectively, then a material suitable for use as a dielectric in a capacitor must have:
1. high k and high x.
2. high k and low x.
3. low k and low x.
4. low k and high x.