In this article, we will learn about the previous year’s objective questions with the answers and explanation of Magnetic Materials. In this article, there will be last year’s ESE questions with answers.
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Also Read Topic Wise Electronics Device and Circuits MCQs For ESE
Objective Question with Answer for Magnetic Materials
1. The magnetic moment in units of both magnetrons of a ferrous ion in any ferrite is
- (a) Zero
- (b) 2
- (c) 4
- (d) 6
2. For a permanent magnetic material
- (a) the residual induction and the coercive field should be large
- (b) the residual induction and the coercive field should be small
- (c) the area of the hysteresis loop should be small
- (d) the initial relative permeability should be large
3. The outermost electronic configuration of a cobalt atom is 3d7 4s2, its magnetic moment is
- (a) 9 Bohr magnetrons
- (b) 7 Bohr magnetrons
- (c) 5 Bohr magnetrons
- (d) 3 Bohr magnetrons
4. The magnetic material in which permanent atomic magnetic dipoles have parallel orientation is termed as which one of the following?
- (a) Diamagnetic
- (b) Paramagnetic
- (c) Ferromagnetic
- (d) Ferrimagnetic
5. Magnetic cores required for RF applications have
- (a) High hysteresis and eddy current losses
- (b) High hysteresis and low eddy current losses
- (c) Low hysteresis and high eddy current losses
- (d) low hysteresis and eddy current losses
6. Ferrites are materials that have
- (a) Low permeability and low dielectric loss
- (b) Low permeability and high dielectric loss
- (c) High permeability and low dielectric loss
- (d) High permeability and High dielectric loss
7. Which one of the following pairs is not correctly matched?
- (a) The temperature below which certain materials are antiferromagnetic and above which they are paramagnetic – Neel Temperature
- (b) Eddy current losses may be minimized by – Laminating the magnetic material
- (c) The temperature at which a conductor becomes a superconductor – Onne’s temperature
- (d) The lower noise is expected in the – film resistors
8. Which material is used for making a permanent magnet?
- (a) Carbon Steel
- (b) Germanium
- (c) Silicon
- (d) Non of the above
9. In Curie law for paramagnetic materials, how is the susceptibility \chi related to absolute temperature T?
- (a) \chi \propto T
- (b) \chi \propto \frac{1}{T}
- (c) \chi \propto T^2
- (d) \chi \propto \frac{1}{T^2}
10. Which one of the following is correct? Ferrites are particularly suited for high-frequency applications because of their
- (a) low distortion
- (b) low eddy current loss
- (c) high conductivity
- (d) high mobility
11. Which one of the following materials is used for making permanent magnets?
- (a) Steel
- (b) Carbon
- (c) Carbon-steel
- (d) Graphites
12. What happens when a paramagnetic material is heated above Curie temperature?
- (a) it becomes diamagnetic
- (b) it becomes non-magnetic
- (c) it becomes ferromagnetic
- (d) it becomes anti-ferromagnetic
13. Ferromagnetic materials show hysteresis in B-H characteristics. As the magnetic field is increased slowly from zero value, what is the first process which sets in the material to give net magnetization?
- (a) Growth of favorably oriented domains at the cost of other domains by reversible boundary displacement
- (b) Growth of favorably oriented domains at the cost of other domains by irreversible boundary displacement
- (c) Domain wall orientation
- (d) A combination of processes (a) and (c) above
14. which one of the following compounds is widely used for making ferrites?
- (a) FeO
- (b) CuO
- (c) MgO
- (d) Fe2O3
15. Which one of the following is not a ferromagnetic material?
- (a) Cobalt
- (b) Iron
- (c) Nickel
- (d) Bismuth
