Testing MCQ Engine and Quiz Maker Bridge

1. Two fixed point charges are kept at the same separation, but the experiment is repeated in a medium of dielectric constant . In a graph of versus , the slope in the medium becomes

2. A proton and an electron have charges

3. Assertion: At the same far distance from a dipole, the axial field is twice the equatorial field in magnitude.
Reason: The far axial field is proportional to , while the far equatorial field is proportional to .

4. The principle of superposition for electrostatic force says that the net force on a charge due to several other charges is found by

5. A charged rod is brought near two identical neutral spheres, one made of aluminium and the other made of plastic. The aluminium sphere shows stronger internal charge redistribution. The main reason is that aluminium

6. A final comparison is made between electric force, electric field, electric flux, and Gauss’s law. The correctly paired statement is

7. A body has charge . The negative sign mainly tells that the charge

8. An insulating plastic strip is charged at one small region by rubbing. Compared with a metal strip, the charge on the plastic strip is more likely to remain near that region because

9. In electrostatics, the symbols and should not be confused because

10. A macroscopic object may appear to have continuously variable charge because

11. Two charges are placed at and . The unit vector from the first charge to the second charge is

12. The convenient Gaussian surface for an infinitely long uniformly charged straight wire is a cylinder coaxial with the wire because

13. An infinite line charge has density . A coaxial cylindrical Gaussian surface of radius and length is used. If both and are doubled, the electric field on the curved surface becomes

14. Study the table for Gauss-law applications and identify the row with the wrong distance dependence.

15. A component form for electrostatic force in one dimension gives . This means the force on has

16. A closed surface encloses . A second closed surface encloses the first surface and also encloses an additional charge . The ratio of net flux through the inner surface to net flux through the outer surface is

17. Two charges and are fixed apart. A small positive test charge is placed between them at a point where the net electric field is zero. Its distance from is

18. A rectangular surface has area . It is placed in a uniform electric field such that the angle between and is . The electric flux is

19. A uniformly charged circular plate has total charge spread over area . Its surface charge density is

20. Near a positively charged conductor surface, the electric field just outside is directed

21. A dipole has at and at . At a point on the positive -axis with , where , the net electric field due to the dipole is directed

22. Assertion: Total charge is found by algebraic addition, not vector addition.
Reason: Electric charge is a scalar quantity with sign.

23. Use the arrangement described below: a charge is placed at the centre of a square. Four identical charges are placed at the four corners of the square. The net force on the central charge is

24. The most convenient Gaussian surface for finding the electric field of an infinite uniformly charged plane sheet is

25. A body has an excess of electrons compared with protons. In elementary electrostatics, the body is described as

26. A plane surface is in a field . Its area vector is . The electric flux through the surface is

27. Assertion: In vector Coulomb-law calculations, changing the definition of the unit vector can change the algebraic sign in the formula but not the physical force.
Reason: The same physical vector must be obtained when the sign convention is used consistently.

28. Two fixed point charges in vacuum are moved into a material medium of greater permittivity, with the same separation. The electrostatic force is expected to

29. The unit of surface charge density is

30. In the arrangement described below, sphere P has charge , sphere Q has charge , and sphere R has charge . If sphere P is tested separately with Q and then with R, the nature of interaction is

31. For a single point charge at the centre, the most convenient Gaussian surface for finding the electric field is a sphere because

32. Two electrons repel each other electrostatically and attract each other gravitationally. The reason these two forces have opposite nature for the same pair is that

33. A uniformly charged conducting spherical shell is in electrostatic equilibrium. The charge resides on the outer surface mainly because

34. At the same large distance from the centre of a dipole, the ratio of the axial field magnitude to the equatorial field magnitude is

35. A tiny body has a deficiency of electrons. Its net charge is

36. A closed Gaussian surface is drawn entirely inside the material of a conductor in electrostatic equilibrium. The net charge enclosed by this Gaussian surface must be

37. Assertion: The electrostatic forces between two point charges have equal magnitudes even if the charges have unequal magnitudes.
Reason: The two forces form an action-reaction pair along the line joining the charges.

38. Study the field-line statements below.
I. The tangent to a field line gives the direction of .
II. Field lines are closer where the field is stronger.
III. Electrostatic field lines intersect at points where the field is very strong.
IV. Field lines start from positive charges and end on negative charges.
The supported statements are

39. A closed surface encloses no charge, but an external charge produces a non-zero electric field at many points on the surface. The correct conclusion is that

40. A force calculation table is prepared for a charge under the influence of two other charges.

The row that needs correction is

41. A charge is placed at the centre of a cube. The flux through one face is . The charge is

42. The Coulomb constant in vacuum is related to the permittivity of free space by

43. The leaves of a gold-leaf electroscope diverge when a charged body touches its metal cap because

44. During rubbing, two initially neutral bodies acquire charges and . This result is a direct sign that

45. A dipole of moment is in a uniform electric field . At an angle , its torque magnitude is and potential energy is . If and , then equals

46. A conducting body has a sharply curved tip and a broad rounded region. In electrostatic equilibrium, the surface charge density is usually larger near the sharper tip. This means the electric field just outside the sharper tip is

47. Two points are at distances and from the same infinitely long uniformly charged wire. If the electric field at distance is , the electric field at distance is

48. A graph of electric field magnitude against for a point charge in vacuum is a straight line through the origin. The slope of this graph is

49. The density expression that would be most suitable for a long thin charged thread is

50. A dipole initially aligned with a uniform electric field is rotated slowly to . If its dipole moment is and the field is , the increase in potential energy is