XAT - Electricity Fundamentals 1000+ MCQ [Solved] PDF Download

1. How many electrons are needed in the valence orbit to give a material's stability?
A.
B.
C.
D.
Answer : A

2. Electric lines of force leave or enter the charge surface at an angle of
A. 30o
B. 45 o
C. 90o
D. depending upon the angle of launch and entry
Answer : C

3. Amorphous solid is also called
A. Crystalline
B. Non- crystalline
C. Polycrystalline
D. Homogenous
Answer : B

4. Permeance of a magnetic circuit is _________ the cross-sectional area of the circuit.
A. directly proportional to
B. inversely proportional to
C. dependent of
D. independent of
Answer : A

5. The idea of preventing one component from affecting another through their common electric and magnetic field is referred to as
A. Hall effect
B. Grounding
C. Shielding
D. Limiting
Answer : C

6. The straight line passing through the two poles of magnet is called
A. Real axis
B. Cartesian axis
C. Magnetic axis
D. Imaginary axis
Answer : C

7. What is the practical unit of electrical energy?
A. Watt
B. Kilowatt-hour
C. Kilowatt-second
D. Megawathour
Answer : B

8. Electrons at the outer shell are called
A. Outer shell electrons
B. Inner shell electrons
C. Semiconductor electrons
D. Valence electrons
Answer : D

9. Which of the following is a natural magnet?
A. Steel
B. Magnesia
C. Lodestone
D. S oft iron
Answer : C

10. The B-H curve for ________ is a straight line passing through the origin.
A. cobalt
B. air
C. hardened steel
D. soft iron
Answer : B

11. A one cubic cm of copper has how many free electrons at room temperature?
A. 80 × 10^18
B. 8.5 × 10^22
C. 20 × 10^10
D. 50 × 10^20
Answer : B

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

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

14. 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

15. One coulomb of charge consists of ________ electrons.
A. 624× 10^16
B. 62.4 × 10^16
C. 6.24 × 10^16
D. 0.624 × 10^16
Answer : A

16. Which of the following has the highest permeability?
A. Soft iron
B. Steel
C. Air
D. Permalloy
Answer : D

17. What is the reluctance of a magnetic path having a length of 2x 10^-3m and crosssectional area of 2.5 x 10^-3 m^2?
A. 6366 A, t/Wb
B. 6000 A, t/Wb
C. 8x10^-3 A, t/Wb
D. 0.8 A, t/Wb
Answer : A

18. If the number of valence electrons of an atom is more than 4a the substance is called
A. a semiconductor
B. a conductor
C. an insulator
D. a semi-insulator
Answer : C

19. 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

20. An alloy of 22 percent iron and 78 per cent nickel.
A. Permalloy
B. Alnico
C. Constantan
D. M anganin
Answer : A

21. Electronic current in a wire is the flow of ____________ electrons.
A. free
B. valence
C. bound
D. loose
Answer : A

22. A principle that states that only two electrons with different spins are allowed to exist in a given orbit
A. Bohr's principle
B. Pauli exclusion principle
C. Avogadro's principle
D. Coulomb's principle
Answer : B

23. The temperature coefficient of resistance of eureka is
A. p ositive
B. negative
C. almost zero
D. i nfinite
Answer : C

24. Who discovered superconductivity in 1911?
A. Kamerlingh Onnes
B. Alex Muller
C. GeoryBednorz
D. Charles Coulomb
Answer : A

25. What is another name for relative permittivity?
A. Dielectric strength
B. Electric intensity
C. Potential gradient
D. Dielectric constant
Answer : D

26. 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

27. Two similar polesa each 1Wba placed 1 m apart in air will experience a repulsive force of
A. 63000 N
B. 63 × 10^-3 N
C. 8 × 10^12 N
D. 796 kN
Answer : A

28. If the number of valence electrons of an atom is less than 4a then the substance is probably
A. a metal
B. an insulator
C. a non-metal
D. a semiconductor
Answer : A

29. Electron is a Greek word for
A. amber
B. Fire
C. Stone
D. Heat
Answer : A

30. How many turns are needed to produce a magnetomotive force of 1000 A.t for a coil with 6 amperes?
A. 6000 turns
B. 600 turns
C. 167 turns
D. 67turns
Answer : C

31. Materials whose permeabilities are slightly greater than that of free space
A. Paramagnetic
B. Non- magnetic
C. Ferromagnetic
D. Diamagnetic
Answer : A

32. An alloy of 40 percent iron and 60 percent nickel.
A. Alnico
B. Permalloy
C. Hipernik
D. Manganin
Answer : C

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

34. What is the typical saturation flux density for most magnetic materials?
A. 4 Wb/m^2
B. 5 Wb/m^2
C. 1 Wb/m^2
D. 2 Wb/m^2
Answer : D

35. Electric potential is a _______ quantity.
A. scalar
B. phasor
C. vector
D. variable
Answer : A

36. A positively charged body has
A. deficit of electrons
B. excess of neutrons
C. excess of electrons
D. deficit of protons
Answer : A

37. A germanium atom has an atomic weight of72. How many neutrons are there?
A.
B.
C.
D.
Answer : B

38. Which of the following statements is TRUE?
A. Silicon dioxide is a good
B. The current carriers in conductors are valence electrons
C. For conductorsa the valence electron are strongly attracted to the nucleus
D. The valence electrons are located in the nucleus of an atom
Answer : B

39. The magnetic field around the conductor is determined by the
A. Size of the conductor
B. Amount of current
C. Current divided by the resistance
D. Resistance divided by the current
Answer : B

40. Which of the following is a diamagnetic material?
A. Aluminum
B. Silver
C. Air
D. Cobalt
Answer : C

41. A 6- V battery is connected across a solenoid of 100 turns having a resistance of 2 ?a Calculate the number of ampere turns?
A.
B.
C.
D.
Answer : C

42. Electric field intensity at a point is numerically equal to ________ at that point.
A. potential gradient
B. potential difference
C. dielectric constant
D. the force
Answer : D

43. The branch of Engineering which deals with the magnetic effect of electric current is known as
A. Magnetism
B. Electromagnetism
C. Electrical engineering
D. Electronics engineering
Answer : B

44. The unit of flux density is
A. Wb/m
B. Tesla
C. At/m
D. N/Wb
Answer : B

45. Steel is hard to magnetize because of its
A. Low permeability
B. High permeability
C. High density
D. High retentivity
Answer : A

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

47. The force acting on a unit n- pole placed at that point is called
A. Magnetic field intensity
B. Electric field intensity
C. Electromagnetic field intensity
D. Intensity magnetization
Answer : A

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

49. Magnetic fields do not interact with
A. Moving permanent magnets
B. Stationary permanent magnets
C. Moving electric charges
D. Stationary electric charges
Answer : D

50. What is the value of the absolute permittivity of air?
A. 8.854 F/m
B. 8.854 × 10^-12 mF/m
C. 8.854× 10^-12 F/m
D. 8.854 × 10^-12 F/m
Answer : C