1000+ Electricity Fundamentals Multiple Choice Question Answer [Solved]

1. The temperature coefficient of resistance of semiconductors is
A. positive
B. zero
C. negative
D. infinite
Answer : C

2. What is the unit of magnetomotive force?
A. Volt
B. Tesla
C. Ampere- turn
D. Weber
Answer : C

3. What type of bond is formed when there exists some form of collective interactions between the (negatively charged) electrons and (positively charged) nuclei in a solid?
A. Ionic
B. Covalent
C. Metallic
D. Van der Waals
Answer : C

4. Which of the following is used by permanent magnets as the magnetic material?
A. iron
B. nickel
C. soft steel
D. hardened steel
Answer : D

5. The ability of a mechanically stressed ferromagnetic wire to recognize rapid switching of magnetization when subjected to a dc magnetic field.
A. Wartheim effect
B. Wiedemann effect
C. Wiegand effect
D. Edison effect
Answer : C

6. The core of a magnetic equipment uses a magnetic material with
A. Least permeability
B. Low permeability
C. Moderate permeability
D. High permeability
Answer : D

7. The permeability of permalloy is
A. Very much greater than permeability of air
B. Slightly greater than permeability of air
C. Slightly less than permeability of air
D. Equal to the permeability of air
Answer : A

8. Which of the following is a paramagnetic material?
A. Carbon
B. Bismuth
C. Copper
D. Oxygen
Answer : D

9. What is the SI unit of specific resistance or resistivity?
A. Ohm-circular mil per inch
B. Ohm-circular mil per foot
C. Ohm-m
D. Ohm-cm
Answer : C

10. The force between two magnetic poles is _______ their pole strengths.
A. directly proportional to
B. the sum of
C. inversely proportional to
D. the product of
Answer : A

11. One of the common application of an air- cored choke.
A. Radio frequency
B. Audio frequency
C. Power supply
D. Power transformer
Answer : A

12. Hysteresis is a phenomenon of _________ in a magnetic circuit.
A. setting up constant flux
B. lagging of H behind B
C. lagging B behind H
D. leading B ahead H
Answer : C

13. This paper does not exhibit electricity because it contains the same number of
A. protons and electrons
B. neutrons and electrons
C. neutrons and positrons
D. atoms
Answer : A

14. The emission of electrons from hot bodies is called
A. Radiation effect
B. Edison effect
C. Skin effect
D. Half effect
Answer : B

15. The temperature coefficient of resistance of conductors is
A. positive
B. zero
C. negative
D. infinite
Answer : A

16. The tiniest element of matter
A. Atom
B. Proton
C. Electron
D. Neutron
Answer : A

17. When the relative permeability of a material is slightly less than 1a it is called _____ material.
A. diamagnetic
B. ferromagnetic
C. paramagnetic
D. non-magnetic
Answer : A

18. A test charge means a charge of
A. -1 C
B. 1 electron
C. +1 C
D. -20 C
Answer : C

19. Electric field intensity is measured in
A. volts/meter
B. Newton/meter
C. Newton-meter
D. Amperes/meter
Answer : A

20. The force of attraction or repulsion between two magnetic poles is inversely proportional to the square of the distance between them. This is known as
A. Newton's first law
B. Faraday's first law of electromagnetic induction
C. Coulomb's first law
D. Coulomb's second law
Answer : D

21. Magnetic field intensity is a ________ quantity.
A. scalar
B. phasor
C. vector
D. variable
Answer : C

22. Materials that have very high permeabilities (hundreds and even thousands times of that of free space)
A. Paramagnetic
B. Non- magnetic
C. Ferromagnetic
D. Diamagnetic
Answer : C

23. Which element has four valence electrons?
A. Conductor
B. Insulator
C. Semiconductor
D. Semi- insulator
Answer : C

24. If the value of 25 a conductor is 1/255 per oCa then the value of 20is
A. 1/300 per oC
B. 1/250 peroC
C. 1/230 per oC
D. 1/260 per oC
Answer : B

25. Small voltages generated by a conductor with current in an external magnetic field.
A. Skin effect
B. Magnetic effect
C. Hall effect
D. Flywheel Effect
Answer : C

26. The property of magnetic materials of retaining magnetism after withdrawal of the magnetizing force is known as
A. Retentivity
B. Reluctivity
C. Resistivity
D. Conductivity
Answer : A

27. What is the SI unit of conductivity?
A. Ohms/m
B. Ohms-m
C. Siemens-m
D. Siemens/m
Answer : D

28. Which of the following materials has permeability slightly less than that of free space?
A. Paramagnetic
B. Non- magnetic
C. Ferromagnetic
D. Diamagnetic
Answer : C

29. Paramagnetic substance has a relative permeability of
A. Slightly less than one
B. Equal to one
C. Slightly equal to one
D. Very much greater than one
Answer : C

30. Hysteresis loss can be reduced by one of the following.
A. Increasing mmf of the circuit
B. Using material narrow hysteresis loop
C. Using ferromagnetic core
D. Laminating the magnetic circuit
Answer : B

31. A magnetic circuit carries a flux iin the iron part and a fluxgin the air gap. What is the leakage coefficient?
A. i/g
B. i × g
C. g/ i
D. i + g
Answer : A

32. A 200-watt lamp working for 24 hours will consume approximately _____ units.
A.
B.
C.
D.
Answer : B

33. The permittivity of a material is given by one of the following formulas.
A. DE
B. E/D
C. D^2/E
D. D/E
Answer : D

34. The force between two charges placed a given distance apart ______ as the relative permittivity of the medium is increased.
A. increases
B. decreases
C. remains unchanged
D. becomes infinite
Answer : B

35. The lagging effect between flux density of the material and the magne
A. Permeance
B. Eddy current
C. Hysteresis
D. R eluctance
Answer : C

36. The conduction of electricity across the surface of a dielectric is called
A. creepage
B. skin effect
C. surface effect
D. crosstalk
Answer : A

37. When a conductor is stationary and the magnetic field is moving or changing the emf induced is called
A. Statically induced emf
B. Mutually induced emf
C. Self induced emf
D. Dynamically induced emf
Answer : A

38. Who demonstrated that there are magnetic effects around every current-carrying conductor and that current-carrying conductors can attract and repel each other just like magnets?
A. Luigi Galvani
B. Hans Christian Oersted
C. Charles Coulomb
D. Andre Ampere
Answer : D

39. What is the relative permittivity of air?
A.
B.
C. 8.854 × 10^-12
D. 4 × 10^7
Answer : B

40. The air space between poles of magnets
A. Air gap
B. Free space
C. Vacuum
D. Atmosphere
Answer : A

41. Who demonstrated the theory of electromagnetic induction in 1831?
A. Michael Faraday
B. Andre Ampere
C. James Clerk Maxwell
D. Charles Coulomb
Answer : A

42. The induced emf in a wire loop that is moved parallel to a uniform magnetic field is
A. Zero
B. Dependent on the area of the loop
C. Dependent on the shape of the loop
D. Dependent on the magnitude of the field
Answer : A

43. If the resistance of a material 2 m long and 2 m^2 in area of cross-section is 1.6 ×10^-8 ?a then its resistivity is
A. 3.2 × 10^-8 ?-m
B. 1.6 × 10^-8 ?-m
C. 0.64 × 10^-8 ?-m
D. 0.16 × 10^-8 ?-m
Answer : B

44. The magnetic energy stored in an inductor is ______ current.
A. Directly proportional to
B. Inversely proportional to
C. Directly proportional to the square of
D. Inversely proportional to the square of
Answer : C

45. If the number of valence electrons of an atom is exactly 4a then the substance is called
A. a semiconductor
B. a conductor
C. an insulator
D. a cryogenic conductor
Answer : A

46. Who developed the electromagnetic theory of light in 1862?
A. Heinrich Rudolf Hertz
B. Wilhelm Rontgen
C. James Clerk Maxwell
D. Andre Ampere
Answer : C

47. What principle states that each electron in an atom must have a different set of quantum numbers?
A. Inclusion principle
B. Exclusion principle
C. Quantum principle
D. Electron principle
Answer : B

48. A law stating that the magnetic susceptibilities of most paramagnetic substances are inversely proportional to their absolute temperatures.
A. Curie's Law
B. Child's Law
C. CR Law
D. Curie-Weiss Law
Answer : A

49. The emf produced in a wire by its motion across a magnetic field does not depend upon the
A. Diameter of the wire
B. Length of the wire
C. Orientation of the wire
D. Flux density of the field
Answer : A

50. The electric potential at a point in air due to a charge is 21 V. If the air is replaced by a medium of relative permittivity of 3a then electric potential at that point will be
A. 63 V
B. 21 V
C. 7 V
D. 42 V
Answer : C