JEE Physics Electrostatic Potential and Capacitance MCQs Set B

Question:

• a) 95 V
• b) 75 V
• c) 150 V
• d) 65 V

Answer: 95 V

Question:

• a) 3 V
• b) 2 V
• c) 6 V
• d) 3.5 V

Answer: 3 V

Question: A parallel plate capacitor after charging is kept connected to a battery and the plates are pulled apart with the help of insulating handles. Now which of the following quantities will decrease ?

• a) All of these
• b) Energy stored
• c) Capacitance
• d) Charge

Answer: All of these

Question:

• a) Increase
• b) Decrease
• c) Remain same
• d) Be halved

Answer: Increase

Question:

• a)

  

• b)

  

• c) 2V
• d) V

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  Two identical capacitors are connected in parallel across a potenial difference V. After they are fully charged, the positive plate of first capacitor is connected to negative plate of second and negative plate of first is connected to positive plate of other. The loss of energy will be

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) Increases continuously
• b) First increases then decreases
• c) Decreases continuously
• d) First decreases then increases

Answer: Increases continuously

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  There is a uniformly charged non conducting solid sphere made of material of dielectric constant one. If electric potential at infinity be zero, then the potential at its surface is V. If we take electric potential at its surface to be zero, then the potential at the centre will be

• a)

  

• b)

  

• c) V
• d) Zero

Answer: 

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 120 J
• b) – 120 J
• c) – 240 J
• d) Zero

Answer: 120 J

Question: If the electric potential on the axis of an electric dipole at a distance ‘r’ from it is V, then the potential at a point on its equatorial line at the same distance away from it will be

• a) 0
• b) – V
• c) 2 V
• d)

  

Answer: 0

Question:

• a) Zero
• b) 5 V
• c) 10 V
• d) 20 V

Answer:  Zero

Question:

• a)

  

• b)

  

• c)

  

• d) Zero

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) Charge will flow from A to B
• b) No charge flows in the wire
• c) Charge will flow from B to A
• d) All charges will reside on the connecting wire

Answer: Charge will flow from A to B

Question:

• a) 5
• b) 9
• c) 6
• d) 4

Answer: 5

Question: Consider a sphere of radius R having charge q uniformly distributed inside it. At what minimum distance from its surface the electric potential is half of the electric potential at its centre?

• a)

  

• b)

  

• c)

  

• d) R

Answer:

Question:  There are two identical capacitors, the first one is uncharged and filled with a dielectric of constant K while the other one is charged to potential V having air between its plates. If two capacitors are joined end to end, the common potential will be

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 64 V/m
• b) – 64 V/m
• c) 16 V/m
• d) – 16 V/m

Answer: 64 V/m

Question: Four charges +q, –q, +q, –q are placed in order on the four consecutive corners of a square of side L. The work done in inter changing the position of any two neighbouring charges of the opposite sign is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c) 2r
• d) r

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c) 3CV
• d) 2CV

Answer:

Question:

• a) 0.4 mJ
• b) 400 mJ
• c) 200 mJ
• d) 0.2 mJ

Answer: 0.4 mJ

Question:

• a) 18
• b) 20
• c) 12
• d) 16

Answer: 18

Question: A parallel plate capacitor with air between the plates has a capacitance C. If the distance between the plates is doubled and the space between the plates is filled with a dielectric of dielectric constant 6, then the capacitance will become

• a) 3C
• b)

  

• c)

  

• d) 12C

Answer: 3C

Question: A capacitor of capacitance C is charged with the help of a 200 V battery. It is then discharged through a small coil of resistance wire embedded in a thermally insulated block of specific heat capacity 2.5 × 10² J/kg and mass 0.1 kg. If the temperature of the block rises by 0.4 K, the value of C is

• a)

  

• b) 50 F
• c)

  

• d) 500 F

Answer:

Question: Electric charges having same magnitude of electric charge 'q ' coulombs are placed at x = 1 m, 2 m, 4 m, 8m ....... so on. If any two consecutive charges have opposite sign but the first charge is necessarily positive, what will be the potential at x = 0?

• a)

  

• b)

  

• c) Zero
• d) Infinity

Answer:

Question: A pellet carrying a charge of 0.5 coulomb is accelerated through a potential of 2000 volts. It attains some kinetic energy equal to

• a) 1000 joule
• b) 1000 kWh
• c) 500 erg
• d) 1000 erg

Answer: 1000 joule

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) Zero
• b) 4q
• c) 2q
• d)

  

Answer: Zero

Question:

• a) 20 N/C
• b) 5 N/C
• c) 4 N/C
• d)

  

Answer: 20 N/C

Question:

• a) Does not change
• b) Increases
• c) Decreases
• d) Initially increases then decreases

Answer: Does not change

Question:

• a) 125
• b) 167
• c) 208
• d) 100

Answer: 125

Question:

• a) 100 V
• b) 50 V
• c) 200 V
• d) Zero

Answer: 100 V

Question: A spherical conductor having charge q and radius r is placed at the centre of a spherical shell of radius R and having charge Q (R > r). The potential difference between the two is

• a) Proportional to q
• b) Independent of both Q and q
• c) Proportional to Q
• d) Dependent on both Q and q

Answer: Proportional to q

Question: The work which is required to be done to make an arrangement of four particles each having a charge +q such that the particles lie at the four corners of a square of side a is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: An electric dipole of dipole moment p is aligned parallel to a uniform electric field E. The energy required to rotate the dipole by 90° is

• a) pE
• b) p²E
• c) Infinity
• d) pE²

Answer: pE

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) Maximum at B
• b) Maximum at C
• c) Maximum at A
• d) Same at all the three points A, B and C

Answer: Maximum at B

Question: Four point charges –Q, –q, 2q and 2Q are placed, one at each corner of the square. The relation between Q and q for which the potential at the centre of the square is zero is

• a) Q = –q
• b) Q = q
• c)

  

• d)

  

Answer: Q = –q

Question: A parallel plate capacitor has a uniform electric field E in the space between the plates. If the distance between the plates is d and area of each plate is A, the energy stored in the capacitor is

• a)

  

• b)

  

• c)

  

• d)

  

Answer: