Electricity Fundamentals MCQ Solved Paper for SBI PO

1. If on looking at any one end of a solenoid; the direction of current flow is found to be clockwise then the end under observation is a south pole. This is known as
A. Right hand rule
B. Left hand rule
C. Cork screw rule
D. End Rule
Answer : D

2. 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

3. 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

4. The ratio of the permeability of material to the permiabiity of air or vacuum.
A. Relative permeability
B. Relative permittivity
C. Relative conductivity
D. Relative reluctivity
Answer : A

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

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

7. 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

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

9. 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

10. The temperature coefficient of resistance of a conductor ______ with an increase in temperature.
A. increases
B. decreases
C. remains the same
D. becomes negative
Answer : B

11. Back emf refers to the
A. Current equal to the applied emf
B. Opposing emf
C. Current opposing the applied emf
D. Voltage opposing the applied emf
Answer : D

12. The electrons in the last orbit of an atom are called _______ electrons.
A. free
B. valence
C. bound
D. thermionic
Answer : B

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

14. The unit of electrical energy is
A. Joule
B. Watt- second
C. Kilowatt hour
D. All of these
Answer : D

15. Electric field intensity at a point due to a given charge ______ if the relative permittivity of the medium decreases.
A. decreases
B. remains unchanged
C. increases
D. b ecomes zero
Answer : C

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

17. If the length and area of cross-section of a wire are doubleda then its resistance
A. becomes four times
B. becomes sixteen times
C. remains the same
D. becomes two times
Answer : C

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

19. 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

20. One of the solid structures in which the position of the atoms or ions are predetermined
A. Crystalline solid
B. Amorphous solid
C. Polycrystalline solid
D. Poly amorphous solid
Answer : A

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

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

23. 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

24. 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

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

26. 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

27. The magnetic potential in a magnetic circuit can be measured in terms of
A. Mmf
B. Emf
C. Farad
D. Coulomb
Answer : A

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

29. An atom or a group of atoms that carries a net electric charge.
A. Positive ion
B. Negative ion
C. Ion
D. Electron
Answer : C

30. 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

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

32. Hipernik is an alloy containing __________ iron and __________ nickel.
A. 40% ; 60%
B. 60% ; 40%
C. 50% ; 50%
D. 70% ; 30%
Answer : A

33. What bond is formed when one or more electrons in the outermost energy orbit of an atom are transferred to another?
A. Ionic
B. Covalent
C. Metallic
D. Van der Waals
Answer : A

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

35. One that has magnetic poles produced by internal atomic structure with no external current necessary
A. Diamagnetic
B. Permanent magnets
C. Paramagnetic
D. Electromagnetic
Answer : B

36. Bonding of atoms that is due to the force of attraction between positive ions and a group of negative ions
A. Ionic bond
B. Covalent Bond
C. Electrostatic Bond
D. Metallic bond
Answer : D

37. The space outside the magnet where its pole have a force of attraction or repulsion on a magnetic pole is called
A. Magnetic field
B. Electric field
C. Electromagnetic field
D. Free Space Field
Answer : A

38. Electric field intensity is a ________.
A. scalar
B. phasor
C. vector
D. variable
Answer : C

39. Whenever a conductor cuts magnetic fluxa an emf is induced in it. This is known as
A. Coulomb's law
B. Joule's law
C. Faraday's law
D. Ohm's law
Answer : C

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

41. The unit of flux is _____ in cgs system.
A. Tesia
B. Gilbert
C. Maxwell
D. Oersted
Answer : C

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

43. The physical motion resulting from the forces of magnetic fields is called
A. Motor action
B. Rotation
C. Repulsion
D. Torque action
Answer : A

44. A current if flowing east along a power line. If the earth's field is neglecteda the direction of the magnetic field below it is
A. North
B. South
C. East
D. West
Answer : A

45. A law establishing the fact that the algebraic su of the rises and drops of the mmf around a closed loop of a magnetic circuit is equal to zero.
A. Kirchhoff's circuital law
B. Maxwell's circuital law
C. Ampere's circuital law
D. Coulomb's circuital law
Answer : C

46. Permanent magnets can be found in
A. electric bells
B. earphones
C. relays
D. dy namic loudspeakers
Answer : B

47. Residual magnetism refers to the flux densitya which exists in the iron core when the magnetic field intensity is
A. Minimized
B. Reduced to zero
C. Maximize
D. Unity
Answer : B

48. One farad equals
A. 1 coulomb/volt
B. 1 newton/coulomb
C. 1 newton-meter
D. 1 volt/second/ampere
Answer : A

49. The mass of proton is __________ the mass of an electron.
A. equal to
B. about 1837 times
C. less than
D. 200 tim es
Answer : B

50. What is the cgs unit of magnetomotive force?
A. Gilbert
B. Ampere- turn
C. Maxwell
D. Weber
Answer : A