Materials and Components – Section 4
31. | Lines of magnetic field cannot intersect. | |||
Answer: Option A |
33. | At T = 0, the resistivity of a perfect single crystal of a metal is | |||||||
Answer: Option A Explanation: At absolute zero temperature resistivity of metals is zero. |
34. | In a polyatomic gas, the types of polarization which exist together are | |||||||
Answer: Option D Explanation: All the three types of polarization exist in polyatomic gases. |
35. | Assertion (A): Metals are better heat conductors than insulators.
Reason (R): If |
|||||||
Answer: Option B |
36. | The number of tightly bound electrons in silicon atom are | |||||||
Answer: Option B Explanation: Silicon has 14 electons and 4 valence electrons. The 10 electrons in the inner orbits are tightly bound. |
37. | Electric dipole moment is usually expressed in debye units. Here, 1 debye unit equals | |||||||
Answer: Option A |
38. | A particle of charge Q coulombs is bound elastically to an equilibrium position with a force constant of f newton per metre. The polarizability of the system is | |||||||
Answer: Option B |
39. | 1 Bohr magneton = ![]() ![]() ![]() ![]() |
|||
Answer: Option A |
40. | An electron (charge –e) is rotating in a circular orbit of radius R, around a proton with charge +e at a constant angular velocity ω. The orbital magnetic dipole moment is | |||||||
Answer: Option A |