Gravitation Mock Test – Class 11 Physics

1. Study the comparison table for a far electric dipole field and identify the mismatched row.

2. A dipole has moment . At a far axial point, a student writes because Coulomb’s law has an inverse-square form. The correction is that the far dipole field varies as

3. A dipole of moment is placed in a uniform electric field . Its potential energy when is

4. A charge is placed at the centre of a square. Four charges of equal magnitude are placed at the corners: top-left , top-right , bottom-right , and bottom-left . The net force on the centre charge is

5. A dipole has moment . At a far axial point from its centre, the approximate field magnitude in vacuum is

6. A circular surface of radius is placed in a uniform electric field. The flux is when the area vector makes with the field. The field magnitude is

7. A point lies inside a uniformly charged spherical shell of radius , and a point lies outside it at distance from the centre. The field magnitudes at and are best described as

8. An isolated conducting sphere has surface charge density and radius . If its charge is kept the same but the radius is changed to , the electric field just outside the new surface becomes

9. At a far axial point of a dipole, the electric field is at distance . At a far equatorial point at distance from the same dipole, the field magnitude is

10. Three charges are fixed at three vertices of an equilateral triangle: , , and . A positive charge is placed at the centre. The direction of the net force on is

11. Assertion: In standard charging by induction, the final charge on the conductor is opposite in sign to the inducing charge.
Reason: During the earthing step, electrons move in a direction decided by the inducing charge, while the inducing body does not touch the conductor.

12. A point charge is kept at the centre of a spherical Gaussian surface. The field is first found from Gauss’s law and then a charge is placed on the surface. The force on is

13. A solid insulating sphere of volume has charge uniformly distributed in it. Its volume charge density is

14. Study the table for a dipole in a uniform electric field and identify the row that needs correction.

15. A plane sheet with charge density produces field . If another identical positive sheet is placed parallel to it, the field on the outer side of the pair is

16. Coulomb’s law and Newton’s law of gravitation are similar in the sense that both

17. Two small charged spheres are apart in vacuum and carry charges and . Using , the magnitude of the force between them is

18. A graph is plotted between electric field magnitude due to a fixed point charge and . The graph is a straight line through the origin. The slope of this graph is

19. A diagram shows electric field lines leaving a charge and ending on a charge , with some lines continuing outward. The best explanation is that

20. Two charges produce forces on a third charge along the same straight line. One contribution is and the other is , where means toward the right. The net force is

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

22. A claim says, “When two neutral bodies are rubbed, one becomes charged because charge is created on it, while the other remains truly unchanged.” The best evaluation is that the claim

23. A positively charged rod is brought near a neutral conducting sphere. The sphere is connected to earth and then isolated while the rod is still present. After the rod is removed, the charge spreads over the sphere because

24. A pair of point charges exerts forces on each other. If the force on charge P due to charge Q has magnitude , then the force on charge Q due to charge P has

25. In the same uniform electric field directed toward the right, an electron released from rest initially accelerates

26. The relation says that when the separation is doubled while the charges stay the same, the force becomes

27. The unit of can be inferred from and . The unit of is

28. A charge is placed at the centre of a spherical Gaussian surface of radius . The electric flux through the sphere is

29. A charge is placed between a negative charge on its left and a positive charge on its right. The force on due to both outer charges is

30. A charge lies inside a closed surface, and a charge lies outside it. A separate uniform external field also passes through the surface. The net flux through the closed surface is

31. Study the constant-symbol table and identify the mismatched row.

32. Consider the following statements about electric charge.
I. Electric charge can be positive or negative.
II. The sign of charge gives a fixed spatial direction.
III. A neutral body has zero net charge.
IV. Like charges repel each other.
The supported set is

33. Consider the following statements about a dipole in an external electric field.
I. In a uniform electric field, the net force on the dipole is zero.
II. In a non-uniform electric field, the dipole may experience a net force.
III. A dipole in a non-uniform field can still experience torque.
IV. A non-uniform field changes the two charges of a dipole into equal positive charges.
The supported statements are

34. A student records four basic electrostatic symbols as follows.

The entry that needs correction is

35. Three identical positive charges are fixed at three corners of a square. A positive charge is placed at the centre. The direction of the net force on is

36. A common mistake while finding net charge is to add only magnitudes. For the charges , , and , that mistake would give , while the actual net charge is

37. The order of operations matters in induction. For a conductor to be left charged using a nearby positive rod, the suitable sequence is

38. A statement says, “Coulomb’s law can be used directly for any two large irregular charged objects by putting their total charges into .” The most suitable correction is that the simple scalar form applies directly when the charges are

39. A charge-density summary is given below.

The row that should be corrected is

40. At the centre of a square, a charge experiences forces due to four corner charges. The two charges at one diagonal are and , while the two charges at the other diagonal are and . The net force on is

41. The elementary charge is commonly taken as

42. A Gaussian surface used in electrostatics is best understood as

43. Study the statements about conservation of charge.
I. The total charge of an isolated system remains constant.
II. Charge can be transferred from one body to another.
III. Ordinary charging means net charge is created from nothing.
IV. Pair production can preserve total charge if equal and opposite charges appear.
The supported statements are

44. A solid sphere has charge distributed throughout its volume rather than only on its surface. The relevant charge density and unit are

45. The SI unit used to measure electric charge is

46. 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

47. The unit of electric field obtained from is

48. 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

49. A neutral molecule has its effective positive charge centre and negative charge centre separated slightly. This molecule can be treated as an electric dipole because

50. A charge distribution has spherical symmetry, but the charge enclosed by a spherical Gaussian surface of radius changes with . The correct Gauss-law strategy is to use