← Back to Physics-II

Capacitor

125 Questions Start Allen Test
All Exams Allen
Q26 Allen CYLINDRICAL CAPACITOR PARALLEL PLATE CAPACITOR & EFFECT OF DIELECTRIC SLAB MCQ
A parallel plate capacitor is charged by a battery. After charging the capacitor, battery is disconnected and distance between the plates is decreased then which of the following statement is correct?
A.
electric field does not remain constant
B.
potential difference is increased
C.
the capacitance decreases
D.
the stored energy decreases
Q27 Allen CYLINDRICAL CAPACITOR PARALLEL PLATE CAPACITOR & EFFECT OF DIELECTRIC SLAB MCQ
A parallel plate capacitor is connected with a battery whose potential difference remains constant. If the plates of the capacitor are shifted apart then the intensity of electric field:
A.
decreases and charge on plates also decreases.
B.
remains constant but charge on plates decreases.
C.
remains constant but charge on the plates increases.
D.
increases but charge on the plates decreases.
Q28 Allen CYLINDRICAL CAPACITOR PARALLEL PLATE CAPACITOR & EFFECT OF DIELECTRIC SLAB MCQ
A parallel plate capacitor is charged with a battery and afterwards the battery is removed. if now, with the help of insulating handles, the distance between the plates is increased, then
A.
charge on capacitor increases and capacity decreases.
B.
potential difference between the plates increases.
C.
capacity of capacitor increases.
D.
value of energy stored in capacitor decreases.
Q29 Allen CYLINDRICAL CAPACITOR PARALLEL PLATE CAPACITOR & EFFECT OF DIELECTRIC SLAB MCQ
Can a metal be used as a medium for dielectric?
A.
Yes
B.
No
C.
Depends on its shape
D.
Depends on dielectric
Q30 Allen CYLINDRICAL CAPACITOR PARALLEL PLATE CAPACITOR & EFFECT OF DIELECTRIC SLAB MCQ
A parallel plate air capacitor has a capacitance C. When it is half filled with a dielectric of dielectric constant 5, the percentage increase in the capacitance will be :-
A.
400%
B.
66.6%
C.
33.3%
D.
200%
Q31 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
The equivalent capacitance between the points A and B in the given diagram is :
A.
$8\mu \mathrm{F}$
B.
$6\mu \mathrm{F}$
C.
$\frac{8}{3}\mu \mathrm{F}$
D.
$\frac{3}{8}\mu \mathrm{F}$
Q32 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
In an adjoining figure three capacitors $C_{1}$ , $C_{2}$ and $C_{3}$ are joined to a battery. The correct condition will be :
A.
$Q_{1} = Q_{2} = Q_{3}$ and $V_{1} = V_{2} = V_{3} = V$
B.
$Q_{1} = Q_{2} + Q_{3}$ and $V = V_{1} + V_{2} + V_{3}$
C.
$Q_{1} = Q_{2} + Q_{3}$ and $V = V_{1} + V_{2}$
D.
$Q_{2} = Q_{3}$ and $V_{2} = V_{3}$
(Symbols have their usual meanings)
Q33 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
The effective capacity of the network between terminals A and B is :
A.
$6\mu \mathrm{F}$
B.
$20\mu \mathrm{F}$
C.
$3\mu \mathrm{F}$
D.
$10\mu \mathrm{F}$
Q34 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
A series combination of two capacitances of value 0.1 Ī¼F and 1Ī¼F is connected with a source of voltage 500 volts. The potential difference in volts across the capacitor of value 0.1 Ī¼F will be:
A.
50
B.
500
C.
45.5
D.
454.5
Q35 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
The value of equivalent capacitance of the combination shown in figure, between the points P and Q is :
A.
3C
B.
2C
C.
C
D.
C/3
Q36 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
The equivalent capacitance between points A and B of the circuit shown will be :
A.
$\frac{2}{3} \mu \mathrm{F}$
B.
$\frac{5}{3}$ Ī¼F
C.
$\frac{8}{3} \mu \mathrm{F}$
D.
$\frac{7}{3} \mu \mathrm{F}$
Q37 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
The effective capacitance between the points P and Q of the arrangement shown in the figure is :
A.
$(1 / 2)\mu \mathrm{F}$
B.
$1 \mu \mathrm{F}$
C.
$2\mu \mathrm{F}$
D.
$1.33\mu \mathrm{F}$
Q38 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
Two spheres of radii $R_{1}$ and $R_{2}$ having equal charges are joined together with a copper wire. If V is the potential of each sphere after they are separated from each other, then the initial charge on both spheres was:
A.
$\frac{V}{k}(R_{1}+R_{2})$
B.
$\frac{V}{2k}(R_{1}+R_{2})$
C.
$\frac{V}{3k}(R_{1}+R_{2})$
D.
$\frac{V}{k}\frac{(R_{1}R_{2})}{(R_{1}+R_{2})}$
Q39 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
Two spheres of radii 1 cm and 2 cm have been charged with $1.5 \times 10^{-8}$ and $0.3 \times 10^{-7}$ coulombs of positive charge. When they are connected with a wire, charge:
A.
will flow from the first to the second
B.
will flow from the second to the first
C.
will not flow at all
D.
may flow either from first to second, or from the second to first, depending upon the length of the connecting wire
Q40 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
Half of the space between a parallel plate capacitor is filled with a medium of dielectric constant K parallel to the plates. If initially the capacity was C, then the new capacity will be:
A.
2KC/(1+K)
B.
C (K+1)/2
C.
CK/(1+K)
D.
KC
Q41 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
Two capacitances $C_{1}$ and $C_{2}$ in a circuit are joined as shown in figure The potential of point A is $V_{1}$ and that of B is $V_{2}$ . The potential of point D will be :
A.
$\frac{1}{2} (V_1 + V_2)$
B.
$\frac{\mathrm{C}_2\mathrm{V}_1 + \mathrm{C}_1\mathrm{V}_2}{\mathrm{C}_1 + \mathrm{C}_2}$
C.
$\frac{\mathrm{C}_1\mathrm{V}_1 + \mathrm{C}_2\mathrm{V}_2}{\mathrm{C}_1 + \mathrm{C}_2}$
D.
$\frac{\mathrm{C}_2\mathrm{V}_1 - \mathrm{C}_1\mathrm{V}_2}{\mathrm{C}_1 + \mathrm{C}_2}$
Q42 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
A circuit has a section AB as shown in the figure with E = 10 V, $C_{1} = 1.0 \mu F$ , $C_{2} = 2.0 \mu F$ and the potential difference $V_{A} - V_{B} = 5 V$ . The voltage across $C_{1}$ is :
A.
Zero
B.
$5\mathrm{V}$
C.
$10\mathrm{V}$
D.
$15\mathrm{V}$
Q43 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
In the circuit diagram shown all the capacitors are in $\mu F$ . The equivalent capacitance between points A & B is (in $\mu F$ ):
A.
$14 / 5$
C.
$3 / 7$
D.
None of these
Q44 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
Two capacitances $C_{1}$ and $C_{2}$ are connected in series; assume that $C_{1} < C_{2}$ . The equivalent capacitance of this arrangement is C, where:
A.
$C < C_{1}/2$
B.
$C_{1}/2 < C < C_{1}$
C.
$C_{1} < C < C_{2}$
D.
$C_{2} < C < 2C_{2}$
Q45 Allen COMBINATION OF CAPACITORS & SHARING OF CHARGES MCQ
In the following circuit the resultant capacitance between A & B is $1\mu F$ . Find the value of C :
A.
$\frac{23}{32}\mu \mathrm{F}$
B.
$\frac{32}{23}\mu \mathrm{F}$
C.
$\frac{13}{23}\mu \mathrm{F}$
D.
$\frac{23}{13}\mu \mathrm{F}$
Q46 Allen CHARGING AND DISCHARGING OF CAPACITORS & CAPACITOR'S CIRCUIT MCQ
A capacitor of capacitance 5 $\mu$ F is connected as shown in the figure. The internal resistance of the cell is 0.5 $\Omega$ . The amount of charge on the capacitor plate is :
A.
0
B.
$5\mu \mathrm{C}$
C.
$10\mu \mathrm{C}$
D.
$25\mu \mathrm{C}$
Q47 Allen CHARGING AND DISCHARGING OF CAPACITORS & CAPACITOR'S CIRCUIT MCQ
In the given circuit, the potential difference across 3 $\mu$ F capacitor will be :
A.
$16\mathrm{V}$
B.
$10\mathrm{V}$
C.
$6\mathrm{V}$
D.
4 V
Q48 Allen CHARGING AND DISCHARGING OF CAPACITORS & CAPACITOR'S CIRCUIT MCQ
If potential of A is 10 V, then potential of B is :
A.
$25 / 3\mathrm{V}$
B.
$50 / 3\mathrm{V}$
C.
$100 / 3\mathrm{V}$
D.
$50\mathrm{V}$
Q49 Allen CHARGING AND DISCHARGING OF CAPACITORS & CAPACITOR'S CIRCUIT MCQ
Capacitance $C_{1} = 2C_{2} = 2C_{3}$ and potential difference across $C_{1}$ , $C_{2}$ and $C_{3}$ are $V_{1}$ , $V_{2}$ and $V_{3}$ respectively then :
A.
$V_{1} = V_{2} = V_{3}$
B.
$V_{1} = 2V_{2} = 2V_{3}$
C.
$2V_{1} = V_{2} = V_{3}$
D.
$2V_{1} = 2V_{2} = V_{3}$
Q50 Allen CHARGING AND DISCHARGING OF CAPACITORS & CAPACITOR'S CIRCUIT MCQ
In the circuit shown in figure, the battery is an ideal one with emf V. The capacitor is initially uncharged. Switch S is closed at time t = 0. The final charge Q on the capacitor is:
A.
$\frac{CV}{2}$
B.
$\frac{CV}{3}$
C.
CV
D.
$\frac{CV}{6}$