1000+ Electricity Fundamentals MCQ for IBPS RRB [Solved]

1. If the solenoid is gripped by the right hand with the fingers pointing the direction of current flowa the outstretched thumb will then point the north pole. This is known as
A. Right hand rule
B. Helix rule
C. End rule
D. Cork screw rule
Answer : B

2. 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

3. 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

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

5. What is the SI unit of conductance?
A. Siemens
B. Mhos
C. Ohms
D. 1/Ohms
Answer : A

6. The electric potential across part AB of a circuit is 5 V; point A being at higher potential. If a charge of 5 Cmoves from A to Ba then energy released as
A. 5 joules
B. 25 joules
C. 10 joules
D. 100 joules
Answer : B

7. States that the ratio of the thermal conductivity is proportional to the absolute temperature for all metals.
A. Wien's displacement law
B. Hartleys law
C. Hall's law
D. Wiedemann Franz law
Answer : D

8. What is the usual value of leakage coefficient for electrical machines?
A. 0.5 to 1
B. 1 to 5
C. 5 to 10
D. 1.15 to 1.25
Answer : D

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

10. What is the SI unit of magnetic flux?
A. Tesla
B. Weber
C. Maxwell
D. Gauss
Answer : B

11. 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

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

13. The ability of a material to conduct magnetic flux through it.
A. Permittivity
B. Reluctivity
C. Conductivity
D. Permeability
Answer : D

14. The process by which an emf and hence current is generated or induced in a conductor when there is a change in the magnetic flux linking the conductor is called
A. Electromagnetic induction
B. Mutual induction
C. Faraday's law
D. Electromagnetic interference
Answer : A

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

16. Which of the following has the least number of valence electrons?
A. Conductor
B. Semiconductor
C. Insulator
D. Semi- insulator
Answer : A

17. How many neutrons does a copper atom have?
A.
B.
C.
D.
Answer : B

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

19. All matters (gasa liquid and solid) are composed of
A. Neutrons
B. Particles
C. Electrons
D. Atoms
Answer : D

20. Lenz's law is the consequence of the law of conservation of
A. Energy
B. Charge
C. Field lines
D. Momentum
Answer : A

21. Magnetic effects of the earth as a huge magnet with north and south poles.
A. Diamagnetic
B. Ferromagnetic
C. Terrestrial magnetism
D. Terrestrial ferromagnetism
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. The force acting on a pole of 5 Wb is 25 N. What is the intensity of the magnetic field?
A. 5 N/Wb
B. 25 N/Wb
C. 125 N/Wb
D. 0.2 N/Wb
Answer : A

24. Which of the following is a vector quantity?
A. Magnetic potential
B. Magnetic field intensity
C. Magnetic permeability
D. F lux density
Answer : B

25. 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

26. The resistivity of a conductor ___________ with an increase in temperature.
A. increases
B. decreases
C. remains the same
D. becomes zero
Answer : A

27. The amount of magnetizing force to counter balance the resid magnetic material is referred to as
A. Reluctivity
B. Susceptivity
C. Coercivity
D. Retentivity
Answer : C

28. 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

29. 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

30. The quantity of magnetism retained by a magnetic material after withdrawal of the magnetizing force is called
A. Leftover magnetism
B. Hysteresis
C. Residual magnetism
D. Coercivity
Answer : C

31. How much is the flux in Weber in the above problem?
A. 2 x 10^-5
B. 2 x 10^-3
C. 2 x 10^5
D. 2 x 10^3
Answer : A

32. Who discovered the most important electrical effects which is the magnetic effect?
A. Hans Christian Oersted
B. Sir Charles Wheatstone
C. Georg Ohm
D. James Clerk Maxwell
Answer : A

33. What is the main advantage of temporary magnets?
A. The magnetic flux can be changed.
B. Hysteresis can be decreased.
C. Magnetic materials can be used.
D. Abundance of ferromagnetic material that can be temporarily magnetized.
Answer : A

34. The magnetic flux through a coil changes. This results to the induced emf acting in a direction as to
A. Oppose the change
B. Aid the change
C. Either oppose or aid the change
D. Neither oppose nor aid the change
Answer : A

35. One ampere- turn is equivalent to _____ gilberts
A.
B.
C.
D.
Answer : B

36. The ratio of the total flux (flux in iron path) to the useful flux (flux in air gap)
A. Leakage flux
B. Leakage current
C. Leakage coefficient
D. Leakage factor
Answer : D

37. 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

38. 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

39. 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

40. A magnetic flux of 2.5 x10^4 Wb through an area of 5 x10^4 square meters results in
A. 5 Wb
B. 0.5 Tesia of flux density
C. 5x 10^-5 Wb of flux
D. 5000 Tesia of flux density
Answer : B

41. If the distance between two magnetic poles decreases by 2 timesa the force between them
A. decreases two times
B. increases four times
C. increases two times
D. decreases four times
Answer : B

42. The force between two magnetic poles is _____ their poles strength.
A. equal to
B. directly proportional to
C. inversely proportional to
D. directly proportional to the square root of
Answer : B

43. The diameter of a hydrogen atom is approximately ______ cm.
A. 1.1 x 10^-6
B. 1.1 x 10^7
C. 1.1 x 10^-8
D. 1.1 x 10^-9
Answer : C

44. Defined as the flux density produced in it due to its own induced magnetism
A. Magnetic field intensity
B. Electric field intensity
C. Electromagnetic field intensity
D. Intensity magnetization
Answer : D

45. A magnetizing force of 1000 AT/m will produce a flux density of __________ i
A. 1.257 mWb/m^2
B. 0.63 Wb/m^2
C. 1.257 Wb/m^2
D. 0.63 mWb/m^2
Answer : A

46. The energy stored in an electrostatic field or electromagnetic field is called
A. Electromagnetic energy
B. Kinetic energy
C. Potential energy
D. R est energy
Answer : C

47. Whenever a flux inking a coil or current changesa an emf is induced in it. This is known as
A. Joule's Law
B. Coulomb's Law
C. Faraday's first law of electromagnetic induction
D. Faraday's second law of electromagnetic induction
Answer : C

48. A law that states that the polarity of the induced voltage will oppose the change in magnetic flux causing the induction.
A. Joule's law
B. Faraday's law
C. Coulomb's law
D. Lenz' law
Answer : D

49. What determines the atomic number of an element?
A. The number of protons
B. The number of electrons
C. The number of neutrons
D. The number of neutrons and protons
Answer : A

50. Three charges of +5 Ca -6 C and +9 C are placed inside a sphere. What is the total flux passing through the surface of sphere?
A. 8 C
B. 14 C
C. 20 C
D. -6 C
Answer : A