__MCQs On Electric charge and Fields For NEET pdf__

__Multiple Choice Questions On Electric charge and Fields with answers__

**1. At a distance r, two equal charges are kept and they exert a force F on each other. What is the force acting on each charge, if the distance between them is doubled and charges are halved?**

(a) F/4

(b) 4 F

(c) F/16

(d) F/8

**Answer: C**

**2. In nature, the electric charge of any system is always equal to__________**

(a) half integral multiple of the least amount of

charge

(b) zero

(c) square of the least amount of charge

(d) integral multiple of the least amount of charge

**Answer: D**

**3. Consider a neutral conducting sphere. A positive point**** charge is placed outside the sphere. The net charge**** on the sphere is then__________**

(a) negative and distributed uniformly over its surface.

(b) negative and appears only at the point on the

sphere closest to the point charge

(c) negative and distributed non-uniformly over its entire surface of the sphere

(d) zero

**Answer: D**

**4. Two point charges placed at a distance ‘r’ in air exert a force ‘F’. The distance at which they exert same force when placed in a certain medium(dielectric constant K) is _______**

(a) rK

(b) r/K

(c) r K

(d) r √K

**Answer:C**

5. What equal charges should to be placed one earth and moon to neutralize their gravitational attraction ? (mass of earth = 1025 kg, mass of moon= 1023 kg)

(a) 8.6 × 10¹³ C

(b) 6.8 × 10²⁶ C

(c) 8.6 × 10³C

(d) 9 × 10⁶ C

**Answer: C**

**6. When a plastic comb is passed through dry hair, the charge acquired by the comb is__________**

(a) always negative

(b) always positive

(c) sometimes negative

(d) none of the above

**Answer: A**

**7. The value of absolute permittivity of free space is______**

(a) 9×10-⁹C-²Nm²

(b) 9×10⁹C-²Nm²

(c) 8.85×10-¹² C²N-¹m-²

(d) 8.85×10¹² C²Nm-²

**Answer: C**

**8. For a dipole, the value of each charge is 10–10 stat coulomb and their separation is 1Å, then its dipole moment is _______**

(a) one debye

(b) 2 debye

(c) 10–3 debye

(d) 3 × 10–20 debye

**Answer: A**

**9. The electric potential and field at a point due to an electric dipole are proportional to _____**

(a) r, r–¹

(b) r–¹, r–²

(c) r–², r–3

(d) r–², r–²

**Answer: C**

**10. When an electric dipole p r is kept in a uniform electric field Er then for what value of angle between p r and E r will the torque be maximum ?**

(a) 90°

(b) 0°

(c) 180°

(d) 45°

**Answer: A**

**11. What will be the ratio of electric field at a point on the axis and an equidistant point on the equatorial line of a dipole________**

(a) 1 : 2

(b) 2 : 1

(c) 4 : 1

(d) 1 : 4

**Answer: B**

**12. For a dipole q = 2 × 10–⁶ C ; d = 0.01m; find the maximum torque on the dipole if**

**E = 5 × 10⁵N/C**

(a) 1 × 10–³ Nm–¹

(2) 10 × 10–³ Nm–¹

(3) 10 × 10–³ Nm

(4) 1 × 10–⁴ Nm

**Answer: C**

**13. Electric field due to a single charge is_____________**

(a) assymetric

(b) cylindrical symmetric

(c) spherical symmetric

(d) none of the above

**Answer: A**

**14. Electric field due to an electric dipole is___________**_

(a) spherical symmetric

(b) cylindrical symmetric

(c) assymetric

(d) none of the above

**Answer: A**

**15. charged conducting sphere has diameter 2.4 m and**** surface charge density 10 µC/m²****Electric flux passing**** through its surface will be **_________

(a) 2 × 10⁷ Nm2/C

(b) 16 × 10⁷ Nm2/C

(c) 1 × 10⁶ Nm2/C

(d) 2.2 × 10⁸Nm2/C

**Answer: A**

**16. A straight cylindrical wire of infinite length produces electric field of strength 9 × 10⁴ N/C at a distance of 10 cm. Linear charge density of the wire is_________**

(a) 0.1 µC/m

(b) 0.5 µC/m

(c) 50 µC/m

(d) 10 µC/m

**Answer: B**

**17. For a uniformly charged sphere, the electric field from its centre _______**

(a) increases linearly upto the surface

(b) decreases linearly upto the surface

(c) remains zero upto the surface

(d) first increases and then decreases upto the surface

**Answer: A**

**18. The dimensional formula of electric flux is________**

(a) L³MT³I¹

(b) L²MT−³I¹

(c) L³MT−³I−¹

(d) L−3³MT−3I

**Answer: C**

**19. What is the value of minimum force acting between two charges placed at 1m apart from each other__________**

(a) Ke

(b) Ke/4

(c) Ke2

(d) Ke2/2

**Answer: C**

**20. An electron of mass me initially at rest moves through a certain distance in a uniform electric field in time t¹. A proton of mass mp also initially at rest takes time t² to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ratio of t²/t¹ is nearly equal to______**

(a) 1

(b) (mp/me)½

(c) (me/mp)½

(d) 1836

**Answer: B**

**21. There is a uniform electric field of strength ****10³ V/m along y–axis. A body of mass 1 g and charge**** 10–⁶C is projected into the field from origin along positive x–axis with a velocity 10 m/s. Its**** speed in m/s after 10 s is :- (neglect gravitation**)

(a) 10

(b) 5 √2

(c) 10√ 2

(4) 2

**Answer: C**

**22. When a plastic comb is passed through dry hair, the charge acquired by the comb is___________**

(a) always negative

(b) always positive

(c) sometimes negative

(d) none of the above

**Answer:A**

**23.The cause of quantization of electric charge is___________**

(a) transfer of electrons

(b) transfer of protons

(c) transfer of integral number of electrons

(d) none of the above

**Answer: C**

**24. At a given distance from the centre of electric dipole, field intensity on axial line is k times the field intensity on equatorial line, where k =**

(a) 2

(b) 4

(c) 1

(d) 3

**Answer: B**

**25. The number of electric lines of force radiating from a closed surface in vacuum is 1.13×1011. The charge enclosed by the surface is__________**

(a) 1C

(b) 1μC

(c) 0.1C

(d) 0.1μC

**Answer: A**