G-MS2D75B7RR

# Worksheet on Electric potential and capacitance

Q1 Equipotential at a great distance from a collection of charges whose total sum is not zero are approximately:

a) spheres

b) planes

c) paraboloids

d) ellipsoids

Q2 The electric potential of earth is taken to be zero because earth is a good :

a) insulator

b) conductor

c) semi-conductor

d) dielectric

Q3 100 Joule of work is performed in carrying a charge of - 5C from infinity to a particular point in an uniform electrostatic field. The potential of this point is:

a) 100 V

b) 5 V

c) - 20 V

d) 20 V

Q4 If three capacitors each of capacitance 9 pF are connected in series, the total capacitance of the combination is :

a) 3 x 10 to the power (-12 F)

b) 2 x 10 to the power (-12 F)

c) 34 x 10 to the power (-12 F)

d) None of these

Q5 Three capacitors of capacitance 2 pF, 3 pF and 4 pF are connected in parallel then the charge on each capacitor if the combination is connected to a 100 V supply is :

a) 200 pC, 300 pC, 400 pC

b) 100 pC, 300 pC 200 pC

c) 400 pC, 200 pC, 200 pC

d) 400 pC, 200 pC, 300 pC

Q6 Work done in carrying 2C charge in a circular path of radius 3m around a charge of 10C is :

a) zero

b) 6.66 J

c) 15 J

d) 60 J

Q7 What is the direction of the lines of force at any point on the equipotential surface?

a) Parallel to it

b) Normal to it

c) Be inclined

d) None of these

Q8 E = - dV/dr. Here negative sign signified that:

a) E is opposite to V

b) E is negative

c) E increases when V decreases

d) E is directed in the direction of decreasing V.

Q9 A charged spherical conductor has potential of 6 V and its radius is 2 m. The electric intensity at its centre is :

a) Zero

b) 3NC to the power (-1)

c) 12NC to the power (-1)

d) None of these

Q10 A proton and an electron are released infinite distance apart and are attracted towards each other. Which of the following statement about their kinetic energy is true?

a) Kinetic energy of electron is more than that of proton

b) Kinetic energy of electron less than that of proton

c) Kinetic energy of electron = kinetic energy of proton

d) None of the above

Q11 What is the change in the electric potential energy if a positive charge is moved from a low potential point to a high potential point?

a) It increases

b) It decreases

c) It will remain the same

d) Nothing definite can be predicated

Q12 Two equal positive charges are kept at points A and B. What will be the change in potential if one move from A to B along the line joining these charges?

a) Potential will continuously decrease

b) Potential will continuously increase

c) Potential will decreases first and then increase

d) Potential will increase first and decrease

Q13 The capacitance of a conductor in vacuum is 10 F. If it is put in a medium of relative permittivity 5, the capacitance will be.

a) unchanged

b) 2F

c) 50F

d) 9 x 10 to the power (9) x 10 F

Q14 A number of charged liquid drops coalesce. Which one of the following quantities does not change?

a) Charge

b) Capacitance

c) Potential

d) Electrostatic Energy

Q15 Which of the following factors does not affect the capacitance of a capacitor?

a) Distance between the plates

b) Material of the plates

c) Area of the plates

d) Curvature of the plates

Q16 Which of the following is correct ? The capacitance of parallel plate capacitor varies inversely as the :

a) area of plates

b) distance between the plates

c) relative permittivity of the medium

d) permittivity of the medium

Q17 Which of the following is blocked by the capacitor?

a) A.C.

b) Both A.C. and D.C.

c) Neither A.C. nor D.C.

d) D.C.,

Q18 If the area of the parallel plates of a capacitor is not equal, then the charges on the plates will be :

a) + Q and - Q

b) + Q1 and - Q

c) + Q and + Q

d) + Q1 and + Q

Q19 The unit of permittivity is same as that of.

c) electric field gradient

Q20 The electric potential at a certain distance from a source charge is 600 V and electric field strength at that point is 150 N/C. What is the distance of the observation point from the source charge?

a) 2 m

b) 3 m

c) 4 m

d) 6 m

Q21 When the separation between two charges is increased, the electric potential of the charges.

a) increases

b) decreases

c) remains the same

d) may increase or decrease

Q22 What is the angle between electric field and equipotential surface?

a) 90 degree always

b) 0 degree always

c) 0 degree to 90 degree always

d) 0 degree to 180 degree always

Q23 Potential on the equatorial line of a dipole is :

a) 1 V

b) zero

c) infinite

d) 180 V

Q24 The electric potential at the surface of an atomic nucleus (Z = 50) of radius 9.0 x 10 to the power (-13) cm is :

a) 9 x 10 to the power (5 volt)

b) 8 x 10 to the power (6 volt)

c) 80 volt

d) 9 volt

Q25 Electrostatic potential V at a point, distant r from a charge q varies as :

a) q/r to the power (2)

b) q to the power (2) r

c) q/r

d) q to the power (2) r to the power (2)

Q26 The capacitance C of a capacitor is :-

a) independent of the charge and potential of the capacitor.

b) dependent on the charge and independent of potential.

c) independent of the geometrical configuration of the capacitor.

d) independent of the dielectric medium between the two conducting surfaces of the capacitor.

Q27 To increase the charge on the plate of a capacitor implies to :-

a) decrease the potential difference between the plates.

b) decrease the capacitance of the capacitor.

c) increase the capacitance of the capacitor.

d) increase the potential difference between the plates.

Q28 The net charge on a capacitor is :-

a) 2q

b) q/2

c) 0

d) infinity

Q29 Capacitors are used in electrical circuits where appliances need rapid :

a) Current

b) Voltage

c) Watt

d) Resistance

Q30 Which of the following is called electrical energy tank ?

a) Resistor

b) Inductance

c) Capacitor

d) Motor

Q31 The potential to which a conductor is raised, depends on :-

a) the amount of charge

b) the geometry and size of the conductor

c) both (1) and (2)

d) None of these

Q32 An uncharged capacitor is connected to a battery. On charging the capacitor :-

a) all the energy supplied is stored in the capacitor.

b) half the energy supplied is stored in the capacitor.

c) the energy stored depends upon the capacity of the capacitor only.

d) the energy stored depends upon the time for which the capacitor is charged.

Q33 The capacity of parallel plate condenser depends on :

a) the type of metal used

b) the thickness of plates

c) the potential difference applied across the plates

d) the separation between the plates.

Q34 When a slab of dielectric medium is placed between the plates of a parallel plate capacitor which is connected with a battery, then the charge on plates in comparison with earlier charge :

a) is less

b) is same

c) is more

d) depends on the nature of the material inserted

Q35 A glass slab is put within the plates of a charged parallel plate condenser. Which of the following quantities does not change?

a) energy of the condenser

b) capacity

c) intensity of electric field

d) charge

Q36 A parallel plate capacitor is connected to a battery and a dielectric slab is inserted between the plates, then which quantity increase :

a) potential difference

b) electric field

c) stored energy

d) E.M.F. of battery

Q37 A parallel plate capacitor is charged by a battery. After charging the capacitor, battery is disconnected and a dielectric plate is inserted between the plates. Then which of the following statements is not correct there is a/an?

a) increase in the stored energy

b) decrease in the potential difference

c) decrease in the electric field

d) increase in the capacitance

Q38 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

Q39 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.

Q40 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.

Q41 Can a metal be used as a medium for dielectric?

a) Yes

b) No

c) Depends on its shape

d) Depends on dielectric

Q42 Two parallel metal plates having charges + Q and - Q face each other with a certain separation between them. If the plates are now dipped in kerosene oil tank, the electric field between the plates will :-

a) increase

b) decrease

c) remain same

d) become zero

Q43 Assertion :- A dielectric slab is inserted between the plates of an isolated charged capacitor. The charge on the capacitor will remain the same.

Reason :- Charge on an isolated system is conserved.

a) A

b) B

c) C

d) D

Q44 Assertion :- On filling the space between the plates of a parallel plate air capacitor with a dielectric, capacity of the capacitor is increased.

Reason :-The same amount of charge can be stored at a reduced potential.

a) A

b) B

c) C

d) D

Q45 Assertion :- The electrostatic potential is necessarily zero at a point, where the electric field strength is zero.

Reason :- A charged particle in an electric field will move from higher potential region to lower potential region.

a) A

b) B

c) C

d) D

Q46 Assertion :- Electric field lines are always perpendicular to the surface of conductor.

Reason :- Electric field is always perpendicular to equipotential surface.

a) A

b) B

c) C

d) D

Q47 Assetion :- Electrostatic field lines are perpendicular to the surface of conductor.

Reason :- Surfaces of a conductor are equipotential.

a) A

b) B

c) C

d) D

Q48 Assertion :- On the sharp edges of charged conductor air get ionized.

Reason :- Potential is higher at the sharp edges of conductor.

a) A

b) B

c) C

d) D

Q49 A charged hollow metal sphere has a radius r. if the potential difference between its surface and a point at distance 3r from the centre is V, the electric intensity at a distance 3r from the centre is :-

a) V/6r

b) V/4r

c) V/3r

d) V/2r

Q50 The electric potential and field at a point due to an electric dipole are proportional to :-

a) r,r to the power (-1)

b) r to the power (-1), r to the power (-2)

c) r to the power (-2), r to the power (-3)

d) r to the power (-2), r to the power (-2)

1) a

2) b

3) c

4) a

5) a

6) a

7) b

8) d

9) a

10) a

11) a

12) c

13) c

14) a

15) b

16) b

17) b

18) a

19) d

20) c

21) d

22) a

23) b

24) b

25) c

26) a

27) d

28) c

29) a

30) c

31) c

32) b

33) d

34) c

35) d

36) c

37) a

38) d

39) a

40) b

41) b

42) b

43) a

44) a

45) d

46) a

47) a

48) c

49) a

50) c