C
(a) (b) 3C
3
C
(c) (d) 5C
4
27. Three capacitors 3uF, 6F and 6uF are
connected in series to a source of
120 V. The potential difference (in volt)
23. An air capacitor is charged with an across the uF capacitor will be
amount of charge q and dipped into an (a) 40 (b) 30
oiltank. If the oil is pumped out, the (c) 40 (d) 60
electric field between the plates of
capacitor will 28. Capacitance between points Aand B is
(a) increase 2uF 2uF
(b) decrease HE
(c) remain the same
(d) becomes zero 3uF
24. Aparallel plate air capacitor has a 12
capacitance 18 F. If the distance (a) (b)F
between the plates is tripled and a
dielectric medium is introduced, the
capacitance becomes 72 uF. The
dielectric constant of the medium is 29. In the figure shown, the effective
(a) 4 (b) 9 capacitance between the points Aand
B, if each has capacitance C, is
(c) 12 (d) 2
C
25. A parallel plate capacitor is made of
two dielectric blocks in series. Effective
dielectric constant K is
(NCERT Exemplar)
A
d
(a) 2C (b)
5
(c) 5C (d)
(a) Kd+Kzd (b) Kd +Kgoe 2
7K+Kg 30. Aparallel plate capacitor is made by
(c) KK,ldh + dy) () 2KK2 stacking nequally spaced plates
(Kdz + Kzd|) K,+K2 connected alternately. If the
capacitance between any two plates is
26. Three capacito seach of capacitance C C. then the resultant capacitance is
and of breakdown voltage V are joined (a) C (b) nC
in series. The capacitance of the (c) (n-) C (d) (n +1)C
combination will be
(a) 2.5 x1o-15J (b) 1.5 x 10-4J
31. In the circuit shown in figure below, the (c)35 x10-3J (d) 7.5x10-12J
potential difference across the 4.5 uF
a
capacitor is energy required to charge
36. The energy
3 uF parallel platereanser of plate
condenser of plate
of
4.5 uF HH separation d and plate area
cross-section A such that the uniform
electric field between the plates E is
6F
(a) (b)
2 Ad Ad
12 V (d)
(c) eEAd 3 Ad
(a) (b) 4 V 37. The potential energy of a charged
(c) 6V
3
(d) 8V
parallel plate capacitor is Un. Ifa slab
of dielectric constant Kis inserted
32. Across each of two capacitors of between the plates, then new potential
capacitance luF and a potential energy will be s isiissc
difference of 10V is applied. Then, (a)
positive plate of one is connected to the
negative plate of the other and negative (c)
Uolatb
(d)
plate of one is connected to the positive K?
plate of the other. After contact, charge
an each plate will be 38. Two condensers C, and C, in a circuit
(a) zero are joined as shown in figure. The
(b) same but non-zero potential of point Ais V, and that of Bis
(c) different but non-zero V,. The potential of point Dwill be
(d) None of the above D B
33. Work done in placing a charge of V2
8x10-l8 Con a condenser of capacity
100uF is (b) CG +C
(a) 16 x1o-32 J (b) 31x100J G+Cq
(c) 4x100J (d) 32 x1o-32J (c) Ch +Cq (d) G4-Ch
34. A 5.0 uF capacitor is charged to a Ch+Cz
potential difference of 800Vand 39. Two identical capacitors, have the same
discharged through a conductor. The capacitance C. One of them is charged
energy given to the conductor during topotential V, and the other to V.
the discharge is Likely charged plates are then
la) 16x10J (b) 3.2 J connected. Then the decrease in energy
(c) 1.6J (d) 4.2 J of the combined system is
35. If the charge on each plate of a (a) -cV-) s (b)-c(v +V)
4
capacitor of 60 F is 3 x 10-C, then 1
energy stored in the capacitor willbe 4 (d)
4
