Electrostatic Potential And Capacitance
Time: 30 Minute
- 1.A parallel plate capacitor has a capacitance of 50 pf in air and 105 pf when immersed in oil. The dielectric constant of the oil is:
- A.
50/105
- B.
1
- C.
2.1
- D.
![]()
- 2.Three capacitors of capacitance 4µ F, 6µF and 12µF are connected first in series and then in parallel. What is the ratio of equivalent capacitance in the two cases?
- A.
2 : 3
- B.
1 : 11
- C.
11 : 1
- D.
1 : 3
- 3.A work of 100 joule is performed in carrying a charge of -5 coulomb from infinity to a particular point in an electrostatic field. The potential of this point is:
- A.
100 V
- B.
5 V
- C.
-20 V
- D.
20 V
- 4.Potential energy of two equal negative point charges 2µC each held 1m apart in air is:
- A.
2 J
- B.
2 eV
- C.
4 J
- D.
0.036 J
- 5.The electric potential at the surface of an atomic nucleus (Z = 50) of radius 9.0 x 10-15 m is:
- A.
80 volt
- B.
8 x volt
![]()
- C.
9 volt
- D.
9 x volt
![]()
- 6.Three different capacitors are connected in series. Then:
- A.
They will have equal charges
- B.
They will have same potential
- C.
Both 1 & 2
- D.
None of these
- 7.When air is replaced by a dielectric medium of constant K, the maximum force of attraction between two charges separated by a distance:
- A.
Becomes times
![]()
- B.
Increases K times
- C.
Remains unchanged
- D.
Decreases K times
- 8.A 2µF capacitor is charged to 100 volt and then its plates are connected by a conducting wire. The heat produced is:
- A.
0.001 J
- B.
0.01 J
- C.
0.1 J
- D.
1 J
- 9.A hollow metal sphere of radius 10 cm is charged such that the potential on its surface is 80 volt. The potential at the centre of the sphere is:
- A.
8 volt
- B.
800 volt
- C.
80 volt
- D.
Zero
- 10.
![The equivalent capacity of the combination C1 = C2 = C3 shown in figure is:
- ProProfs]( "The equivalent capacity of the combination C1 = C2 = C3 shown in figure is:")
The equivalent capacity of the combination C1 = C2 = C3 shown in figure is:- A.
2 C
- B.
C
- C.
C / 2
- D.
None of these
- 11.The magnitude of electric field E in the annular region of a charged cylindrical capacitor.
- A.
Is the same throughout
- B.
Is higher near the outer cylinder than near the inner cylinder
- C.
Varies as 1/r, where r is the distance from the axis
- D.
Varies as 1/ , where r is the distance from the axis.
![]()
- 12.A parallel plate capacitor is made by stocking n equally spaced plates connected alternately. If the capacitance between any two plates is x, then the total capacitance is:
- A.
Nx
- B.
N/x
- C.
X
- D.
(n – 1) x
- 13.Three capacitors each of capacity 4 µF are to be connected in such a way that the effective capacitance is 6 µF. This can be done by:
- A.
Connecting all of them in series
- B.
Connecting all of them in parallel
- C.
Connecting two in series and one in parallel
- D.
Connecting two in parallel and one in series
- 14.A 800 µF capacitor is charged at the steady rate of 50 µC/sec. How long will it take to raise its potential to 10 volt?
- A.
160 s
- B.
50 s
- C.
10 s
- D.
500 s
- 15.If there are n capacitors in parallel connected to V volt source, then energy stored is equal to:
- A.
CV
- B.
C
![]()
- C.
![]()
- D.
nC
![]()
Questions: 15 | Attempts: 9506 | Last updated: Dec 3, 2014
-
Sample QuestionThe Gaussian surface for calculating the electric field due to a charge distribution is:
Questions: 15 | Attempts: 2261 | Last updated: Apr 1, 2014
-
Sample QuestionA parallel plate capacitor has a capacitance of 50 pf in air and 105 pf when immersed in oil. The dielectric constant of the oil is:
Questions: 10 | Attempts: 35903 | Last updated: Sep 3, 2020
-
Sample QuestionWhich of the following is a conversion from chemical energy to thermal energy?
Back to top