1. The capacitance of a metallic sphere will be 1 \[\mu F\] , if its
radius is nearly
a) 9 km
b) 10 m
c) 1.11 m
d) 1.11 cm
Explanation:
2. A parallel plate capacitor of plate area A and plate
separation d is charged to potential V and then the battery
is disconnected. A slab of dielectric constant k is then
inserted between the plates of the capacitors so as to fill the
space between the plates. If Q, E and W denote
respectively, the magnitude of charge on each plate, the
electric field between the plates (after the slab is inserted)
and work done on the system in question in the process of
inserting the slab, then state incorrect relation from the
following
a) \[Q=\frac{\epsilon_{0}AV}{d}\]
b) \[W=\frac{\epsilon_{0}AV^{2}}{2kd}\]
c) \[E=\frac{V}{kd}\]
d) \[W=\frac{\epsilon_{0}AV^{2}}{2d}\left(1-\frac{1}{k}\right)\]
Explanation:
3.The capacitance of a parallel plate condenser does not
depend on
a) Area of the plates
b) Medium between the plates
c) Distance between the plates
d) Metal of the plates
Explanation: Metal of the plates
4. Between the plates of a parallel plate condenser there is
1mm thick paper of dielectric constant 4. It is charged at 100 volt. The electric field in volt / metre between the
plates of the capacitor is
a) 100
b) 100000
c) 25000
d) 4000000
Explanation:
5. The electric field between the two spheres of a charged
spherical condenser
a) Is zero
b) Is constant
c) Increases with distance from the centre
d) Decreases with distance from the centre
Explanation:
6.The distance between the plates of a parallel plate capacitor
is d . A metal plate of thickness d / 2 is placed between the
plates. The capacitance would then be
a) Unchanged
b) Halved
c) zero
d) Doubled
Explanation:
7. An uncharged capacitor is connected to a battery. On
charging the capacitor
a) All the energy supplied is stored in the capacitor
b) Half the energy supplied is stored in the capacitor
c) The energy stored depends upon the capacity of the
capacitor only
d) The energy stored depends upon the time for which the
capacitor is charged
Explanation: In charging of capacitor half of the supplied energy is stored in the capacitor.
8. A capacitor is kept connected to the battery and a dielectric
slab is inserted between the plates. During this process
a) No work is done
b) Work is done at the cost of the energy already stored in
the capacitor before the slab is inserted
c) Work is done at the cost of the battery
d) Work is done at the cost of both the capacitor and the
battery
Explanation: In this process capacity increases, so battery supplies additional charge to capacitor.
9. The capacitance of an air capacitor is \[15\mu F\] the separation
between the parallel plates is 6 mm . A copper plate of 3 mm
thickness is introduced symmetrically between the plates.
The capacitance now becomes
a) 5 \[\mu F\]
b) 7.5 \[\mu F\]
c) 22.5 \[\mu F\]
d) 30 \[\mu F\]
Explanation:
10. An air capacitor is connected to a battery. The effect of
filling the space between the plates with a dielectric is to
increase
a) The charge and the potential difference
b) The potential difference and the electric field
c) The electric field and the capacitance
d) The charge and the capacitance
Explanation:
