2. ELECTROSTATIC POTENTIAL AND CAPACITANCE ( Objective Question Answer 2022 )
1. The dimensions of fall of potential per unit distance are given by :
(A) [MLT-3A-1]
(B) [ML2T-2A-1]
(C) [ML2T-2A-3]
(D) [MLT-2A-2]
| Answer ⇒ C |
2. Which of the following is blocked by a capacitor ?
(A) A.C.
(B) D.C.
(C) Both A.C. and D.C.
(D) Neither A.C. nor D.C.
| Answer ⇒ B |
3. Two copper spheres of the same radius, one solid and the other hollow, are charged to the same potential. Which will have more charge ?
(A) Solid sphere
(B) Hollow sphere
(C) Both will have an equal charge
(D) None of these
| Answer ⇒ C |
4. The capacitance of a capacitor will decrease if we introduce a slab of:
(A) copper
(B) aluminium
(C) zinc
(D) None of these
| Answer ⇒ D |
5. The amount of work required to increase the distance between – 6μC and 4uC from 6 cm to 18 cm will be :
(A) 1.8 J
(B) 2.4 J
(C) 1.8 μ J
(D) 2.4 μ J
| Answer ⇒ B |
6. An electron initially at rest is accelerated through a potential difference of one volt. The energy gained by electron is :
(A) 1 J
(B) 1.6 x 10-19 J
(C) 10-19 J
(D) None of these
| Answer ⇒ B |
7. A bird sitting on a high power line :
(A) gets killed instantly
(B) gets a mild shock
(C) gets a fatal shock
(D) is not affected practically
| Answer ⇒ D |
8. Choose the SI unit of electric potentia energy :
(A) Joule
(B) Coulomb
(C) Netwon per coulomb
(D) Erg
| Answer ⇒ A |
9. The capacitance of earth, viewed as spherical conductor of radius 6408 km is.
(A) 1420 μF
(B) 712 μF
(C) 680 μF
(D) 540 μF
| Answer ⇒ B |
10. A capacitor is connected to a cell of emin having some internal resistance r, the potential across the :
(A) cell is < E
(B) cell is E
(C) capacitor is > E
(D) capacitor is E
| Answer ⇒ B |
11. If a +ve charge is moved from low to high potential region, the electric potentiall energy :
(A) decreases
(B) increases
(C) remain the same
(D) may increase or decrease
| Answer ⇒ B |
12. Minimum number of capacitor of 2μF each required to obtain a capacitance of 5μF will be :
(A) 4
(B) 3
(C) 5
(D) 6
| Answer ⇒ A |
13. When a dielectric slab is introduced between the plates of a parallel plate capacitor which remains connected to a battery then charge on the plates relative to earlier charge is :
(A) more
(B) less
(C) less or may be more
(D) same
| Answer ⇒ A |
14. Choose the vector physical quantity :
(A) Electric flux
(B) Electric potential
(C) Electric potential energy
(D) Electric intensity
| Answer ⇒ D |
15. The surface density of charge is measure :
(A) Cm-1
(B) Cm-2
(C) Cm-3
(D) JC-1
| Answer ⇒ B |
16. A polythene piece rubbed with wool is found to have a negative charge of 6.4 x 10-9c. How many electrons have been transferred during the process ?
(A) 4 x 1012
(B) 4 x 1011
(C) 4 x 1010
(D) None of these
| Answer ⇒ C |
17. In the above question :
(A) no electrons are transferred
(B) electrons are transferred from wool to x polythene
(C) electrons are transferred from polythene to wool
(D) nothing can be decided
| Answer ⇒ B |
18. In previous question, mass transferred to polythene is :
(A) 3.64 x 10-20 kg
(B) 4 x 10-28 kg
(C) 4 x 1010 kg
(D) None of these
| Answer ⇒ A |
19. What is the number of electrons in 100 g water ?
(A) 3.35 x 1024
(B) 3.35 x 1025
(C) 6.02 x 1023
(D) None of these
| Answer ⇒ A |
20. A uniform electric field of 10 NC-1 exists in the vertically downward direction. What is the increase in the electric potential as one goes up through a height of 300 cm ?
(A) 15 V
(B) 30 V
(C) 45 V
(D) None of these
| Answer ⇒ B |
21. The electric potential of earth is taken as :
(A) zero
(B) infinity
(C) unity
(D) None of these
| Answer ⇒ A |
22. The capacity of an isolated sphere is increases n times when it is enclosed by an earth concentric sphere. The ratio of their radii is :
| Answer ⇒ D |
23. The capacity of an isolated conducting sphere of radius R is proportional to :
(A) R2
(B) 1/R2
(C) 1/R
(D) R
| Answer ⇒ D |
24. The value of a charge q at the centre of two equal and like charges Q so that the three charges are in equilibrium is :
(A) Q
(B) Q/2
(C) Q/4
(D) -Q/4
| Answer ⇒ D |
25. Coulomb’s law is given by F= Kq1q2rn, where n is :
(A) 1/2
(B) -2
(C) 2
(D) -1
| Answer ⇒ A |
26. When dielectric is placed into the gap of parallel plate capacitor, the capacitance of capacitor ?
(A) decreases
(B) increases
(C) remains same
(D) None of these
| Answer ⇒ B |
27. What is the net charge on a charged capacitor ?
(A) Zero
(B) 1μC
(C) 10
(D) Infinity
| Answer ⇒ A |
28. A capacitor of capacity C1 is charged upto V volts and then connected to an uncharged capacitor of capacity C2. Then final potential difference across each will be :
| Answer ⇒ C |
29. Conducting sphere of radius R1 is covered by concentric sphere of radius R2. Capacity of this combination is proportional to :
| Answer ⇒ D |
30. Let V be the electric potential at a given point, then the electric field Fx along x- direction at that point is given by :
| Answer ⇒ C |
31. The electric potential due to a small electric dipole at a large distance from the centre of the dipole is proportional to :
(A) r
(D) 1/r
(C) 1/r2
(D) 1/r3
| Answer ⇒ C |
32. A series combination of there capacitors of capacitance lμF, 2μF and 8μF is connected in series to a battery of emf 13 Volt. The potential difference across the plates of 2μF capacitor will be :
(A) IV
(B) 8V
(C) 13/3 V
(D) 4V
| Answer ⇒ D |
Class 12th physics objective question in English
