Multiple Choice Question/ Objective question Electrical Material Part -4 for Competition Exam

Q.1. Superconductors are becoming popular for use in

      (a)  Generating very strong magnetic field

      (b)  Manufacture of bubble memory

      (c)  Generating electrostatic field

      (d)  None of the above
Ans (a)

Q.2. High resistivity materials are used in

      (a)  Precision instrument

      (b)  Heating Instruments

      (c)  Incandescent lamp

      (d)  All of the above
Ans (d)

Q.3. Mercury as an electric contact material is

      (a)  A Liquid

      (b)  A Metal

      (c)  A Metal liquid

      (d)   A gas
Ans (c)

Q.4. A conductor have transport phenomena of electron due to

      (a)  Electric field

      (b)  Magnetic field

      (c)  Electromagnetic filed

      (d)  None of the above
Ans (a)

Q.5. By increasing impurity content in the metal alloy the residual resistivity always

      (a)  Decrease

      (b)  Increase

      (c)  Remain constant

      (d) insulator
Ans (a)

Q.6. In n type semi conductor added impurity is

      (a)  Pentavalent

      (b)  Divalent

      (c)  Trivalent

      (d)  Tetravalent
Ans (a)

Q.7. N-type semiconductor is an example of

      (a)  Extrinsic semiconductor

      (b)  Intrinsic semiconductor

      (c)  Super conductor

      (d)  Insulator
Ans (a)

Q.8. All semiconductors in their last orbit have

      (a)  8 electrons

      (b)  6 electrons

      (c)  4 electrons

      (d)  2 electrons
Ans (c)

Q.9. Holes are majority carriers in

      (a)   P-type semiconductors

      (b)   N-type semiconductors

      (c)   Super conductor

      (d)   Insulator
Ans (a)

Q.10. Germanium possesses

      (a)   one valence electrons

      (b)   two valence electrons

      (c)   three valence electrons

      (d)   four valence electrons
Ans (d)

Q.11. Hall effect may be used for which of the following?

      (a)   Determining whether the semiconductor is p or n type.

      (b)   Determining the carrier concentration

      (c)   Calculating the mobility

      (d)   All of the above

Ans (d)

Q.12. A pure semiconductor under ordinary conditions behaves like

      (a)  A conductor

      (b)  An insulator.

      (c)  A magnetic material

      (d)  All of the above
Ans (b)

Q.13. In p-type semiconductor the majority carriers are

      (a)  Holes

      (b)  Electrons

      (c)  Positive ion

      (d)  Negative ion
Ans (a)

Q.14. For germanium the forbidden gap is

      (a)  0.15ev

      (b)  1.25ev

      (c)  0.25ev

      (d)  0.7ev
Ans (c)

Q.15. A ferrite core has less eddy current loss than an iron core because ferrites have

      (a)  High resistances

      (b)  Low resistances

      (c)  Low permeability

      (d)  High hysteresis
Ans (a)