NEET Physics Electric Field Electric Field Lines and Electric Dipole MCQs

Question: The electric field at a point on equatorial line of a dipole and direction of the dipole moment

a) will be in opposite direction

b) will be perpendicular

c) are not related

d) will be parallel

Answer: will be in opposite direction

Question:

a)

b)

c)

d)

Answer:

Question:  A metallic sphere is placed in a uniform electric field. The line of force follow the path (s) shown in the figure as

a) 4

b) 3

c) 2

d) 1

Answer:  4

Question:  Three infinitely long charge sheets are placed as shown in figure. The electric field at point P is

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d) None of these

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:  An electric dipole is placed at an angle of 30° to a non-uniform electric field. The dipole will experience

a) a torque as well as a translational force

b) a torque only

c) a translational force only in the direction normal to the direction of the field

d) a translational force only in the direction of the field

Answer:  a torque as well as a translational force

Question:

a) from negative charge to positive charge

b) perpendicular to the line joining the two charges drawn at the centre and pointing upward direction

c) perpendicular to the line joining the two charges drawn at the centre and pointing downward direction

d) from positive charge to negative charge

Answer: from negative charge to positive charge

Question:  The electric field near a conducting surface having a uniform surface charge density is given by

a)

b)

c)

d) None of these

Answer:

Question:  Select the correct statements from the following

I. Inside a charged or neutral conductor, electrostatic field is zero.

II. The electrostatic field at the surface of the charged conductor must be tangential to the surface at any point.

III. There is no net charge at any point inside the conductor.

a) I and III

b) I, II and III

c) I and II

d) II and III

Answer: I and III

Question:  In the figure, charge q is placed at origin O. When the charge q is displaced from its position the electric field at point P changes

a)

b)

c)

d)

Answer:

More Questions.....................................

Question:  Which of the following graphs shows the correct variation in magnitude of torque on an electric dipole rotated in a uniform electric field from stable equillibrium to unstable equillibrium?

a)

b)

c)

d)

Answer:

Question:  Assertion  :   A point charge is brought in an electric field, the field at a nearby point will increase or decrease, depending on the nature of charge.

Reason     :  The electric field is independent of the nature of charge.

a) Assertion is correct, reason is incorrect

b) Assertion is incorrect, reason is correct

c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Answer: Assertion is correct, reason is incorrect

Question: A rod of length 2.4 m and radius 4.6 mm carries a negative charge of 4.2 × 10^–7 C spread uniformly over it surface. The electric field near the mid–point of the rod, at a point on its surface is

a) –6.7 × 10⁵ N C^–1

b) –8.6 × 10⁵ N C^–1

c) 8.6 × 10⁴ N C^–1

d) 6.7 × 10⁴ N C^–1

Answer:  –6.7 × 10⁵ N C^–1

Question:  If electric field in a region is radially outward with magnitude E = Ar, the charge contained in a sphere of radius r centred at the origin is

a)

b)

c)

d)

Answer:

Question:

a) –5.6 × 10^–11 N/C

b) –4.8 × 10^–15 N / C

c) –1.6 × 10^–19 N/C

d) –3.2 × 10^–19 N / C

Answer:  –5.6 × 10^–11 N/C

Question: The insulation property of air breaks down when the electric field is 3 × 10⁶ Vm^–1. The maximum charge that can be given to a sphere of diameter 5 m is approximately

a) 2 × 10^–3 C

b) 2 × 10^–5 C

c) 2 × 10^–2 C

d) 2 × 10^–4 C

Answer: 2 × 10^–3 C

Question:  ABC is an equilateral triangle. Charges +q are placed at each corner as shown in fig. The electric intensity at centre O will be

a) zero

b)

c)

d)

Answer:  zero

Question:

a) Zero

b)

c)

d)

Answer:  Zero

Question: The number of electric lines of force that radiate outwards from one coulomb of charge in vacuum is

a) 1.13 × 10¹¹

b) 0.61 × 10¹¹

c) 1.13 × 10¹⁰

d) 0.61 × 10⁹

Answer:  1.13 × 10¹¹

Question:

a) 6.25 × 10⁷ N/C

b) 13.1 × 10¹¹ N/C

c) 9.28 × 10⁷ N/C

d) 20.5 × 10⁷ N/C

Answer: 6.25 × 10⁷ N/C

Question:  Intensity of an electric field (E) depends on distance r, due to a dipole, is related as

a)

b)

c)

d)

Answer:

Question:  If the dipole of moment 2.57 × 10^–17 cm is placed into an electric field of magnitude 3.0 × 10⁴ N/C such that the fields lines are aligned at 30° with the line joining P to the dipole, what torque acts on the dipole?

a) 3.855 × 10^–13 Nm

b) 7.7 × 10^–15 Nm

c) 7.7 × 10^–13 Nm

d) 3.855 × 10^–15 Nm

Answer: 3.855 × 10^–13 Nm

Question:  An electric dipole is placed at an angle of 30° with an electric field of intensity 2 × 10⁵ NC^–1, It experiences a torque of 4 Nm. Calculate the charge on the dipole if the dipole length is 2 cm.

a) 2 mC

b) 8 mC

c) 4 mC

d) 6 mC

Answer:  2 mC

Question:  On decreasing the distance between the two charges of a dipole which is perpendicular to electric field and decreasing the angle between the dipole and electric field, the torque on the dipole

a) decreases

b) cannot be predicted

c) remains same

d) increases

Answer:  decreases

Question:  Assertion : On going away from a point charge or a small electric dipole, electric field decreases at the same rate in both the cases.
Reason : Electric field is inversely proportional to square of distance from the charge or an electric dipole.

a) Assertion is incorrect, reason is correct.

b) Assertion is correct, reason is incorrect

c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer:  Assertion is incorrect, reason is correct.

Question: The electric field at a point on equatorial line of a dipole and direction of the dipole moment

a) will be in opposite direction

b) will be perpendicular

c) are not related

d) will be parallel

Answer:  will be in opposite direction

Question:

a)

b)

c)

d)

Answer:

Question:  A metallic sphere is placed in a uniform electric field. The line of force follow the path (s) shown in the figure as

a) 4

b) 3

c) 2

d) 1

Answer:  4

Question:  Three infinitely long charge sheets are placed as shown in figure. The electric field at point P is

a)

b)

c)

d)

Answer:

Question:

a)

b)

c)

d) None of these

Answer:

Question:

a)

b)

c)

d)

Answer:

Question:  An electric dipole is placed at an angle of 30° to a non-uniform electric field. The dipole will experience

a) a torque as well as a translational force

b) a torque only

c) a translational force only in the direction normal to the direction of the field

d) a translational force only in the direction of the field

Answer: a torque as well as a translational force

Question:

a) from negative charge to positive charge

b) perpendicular to the line joining the two charges drawn at the centre and pointing upward direction

c) perpendicular to the line joining the two charges drawn at the centre and pointing downward direction

d) from positive charge to negative charge

Answer: from negative charge to positive charge

Question:  The electric field near a conducting surface having a uniform surface charge density is given by

a)

b)

c)

d) None of these

Answer:

Question:  Select the correct statements from the following

I. Inside a charged or neutral conductor, electrostatic field is zero.

II. The electrostatic field at the surface of the charged conductor must be tangential to the surface at any point.

III. There is no net charge at any point inside the conductor.

a) I and III

b) I, II and III

c) I and II

d) II and III

Answer:  I and III

Question:  In the figure, charge q is placed at origin O. When the charge q is displaced from its position the electric field at point P changes

a)

b)

c)

d)

Answer:

Question:  Which of the following graphs shows the correct variation in magnitude of torque on an electric dipole rotated in a uniform electric field from stable equillibrium to unstable equillibrium?

a)

b)

c)

d)

Answer:

Question:  Assertion : A point charge is brought in an electric field, the field at a nearby point will increase or decrease, depending on the nature of charge.
Reason    : The electric field is independent of the nature of charge.

a) Assertion is correct, reason is incorrect

b) Assertion is incorrect, reason is correct

c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Answer: Assertion is correct, reason is incorrect

Question:  A rod of length 2.4 m and radius 4.6 mm carries a negative charge of 4.2 × 10^–7 C spread uniformly over it surface. The electric field near the mid–point of the rod, at a point on its surface is

a) –6.7 × 10⁵ N C^–1

b) –8.6 × 10⁵ N C^–1

c) 8.6 × 10⁴ N C^–1

d) 6.7 × 10⁴ N C^–1

Answer: –6.7 × 10⁵ N C^–1

Question:  If electric field in a region is radially outward with magnitude E = Ar, the charge contained in a sphere of radius r centred at the origin is

a)

b)

c)

d)

Answer:

Question:

a) –5.6 × 10^–11 N/C

b) –4.8 × 10^–15 N / C

c) –1.6 × 10^–19 N/C

d) –3.2 × 10^–19 N / C

Answer: –5.6 × 10^–11 N/C

Question: The insulation property of air breaks down when the electric field is 3 × 10⁶ Vm^–1. The maximum charge that can be given to a sphere of diameter 5 m is approximately

a) 2 × 10^–3 C

b) 2 × 10^–5 C

c) 2 × 10^–2 C

d) 2 × 10^–4 C

Answer:  2 × 10^–3 C

Question:  ABC is an equilateral triangle. Charges +q are placed at each corner as shown in fig. The electric intensity at centre O will be

a) zero

b)

c)

d)

Answer:  zero

Question:

a)  Zero

b)

c)

d)

Answer:  Zero

Question: The number of electric lines of force that radiate outwards from one coulomb of charge in vacuum is

a) 1.13 × 10¹¹

b) 0.61 × 10¹¹

c) 1.13 × 10¹⁰

d) 0.61 × 10⁹

Answer:  1.13 × 10¹¹

Question:

a) 6.25 × 10⁷ N/C

b) 13.1 × 10¹¹ N/C

c) 9.28 × 10⁷ N/C

d) 20.5 × 10⁷ N/C

Answer: 6.25 × 10⁷ N/C

Question:  Intensity of an electric field (E) depends on distance r, due to a dipole, is related as

a)

b)

c)

d)

Answer:

Question:  If the dipole of moment 2.57 × 10^–17 cm is placed into an electric field of magnitude 3.0 × 10⁴ N/C such that the fields lines are aligned at 30° with the line joining P to the dipole, what torque acts on the dipole?

a) 3.855 × 10^–13 Nm

b) 7.7 × 10^–15 Nm

c) 7.7 × 10^–13 Nm

d) 3.855 × 10^–15 Nm

Answer: 3.855 × 10^–13 Nm

Question: An electric dipole is placed at an angle of 30° with an electric field of intensity 2 × 10⁵ NC^–1, It experiences a torque of 4 Nm. Calculate the charge on the dipole if the dipole length is 2 cm.

a) 2 mC

b) 8 mC

c) 4 mC

d) 6 mC

Answer: 2 mC

Question: On decreasing the distance between the two charges of a dipole which is perpendicular to electric field and decreasing the angle between the dipole and electric field, the torque on the dipole

a) decreases

b) cannot be predicted

c) remains same

d) increases

Answer: decreases

Question:  Assertion :  On going away from a point charge or a small electric dipole, electric field decreases at the same rate in both the cases.
Reason    :  Electric field is inversely proportional to square of distance from the charge or an electric dipole.

a) Assertion is incorrect, reason is correct.

b) Assertion is correct, reason is incorrect

c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer:  Assertion is incorrect, reason is correct.