Electricity Fundamentals 1000+ MCQ with answer for SBI Clerk

1. A factor used to correct for the electrostatic forces of the more distant ions in an ionic solid.
A. Avogadro's number
B. Planck's constant
C. Boltzmann's constant
D. Madelung constant
Answer : D

2. The magnetic field inside a solenoid
A. is zero
B. is uniform
C. increases with distance from the axis
D. decreases with distance from the axis
Answer : B

3. The reluctance of the magnetic circuit is ________ relative permeability of the material comprising the circuit.
A. directly proportional to
B. inversely proportional to
C. independent of
D. dependent of
Answer : B

4. The property of a material which opposes the creation of magnetic flux in it
A. Resistance
B. Reluctance
C. Permeance
D. Conductance
Answer : B

5. 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

6. Calculate the permeability (in T/A. t/m) of a magnetic material that has a relative permeability of 300
A. 3.78 x 10^4
B. 3.78 x 10^-5
C. 3.78 x 10^-3
D. 3.78 x 10^-6
Answer : A

7. Core materials of a good relay have _________ hysteresis loop.
A. large
B. narrow
C. very large
D. very narrow
Answer : B

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

9. The simplest type of atom to exist is the ______ atom.
A. Helium
B. Hydrogen
C. Boron
D. Oxygen
Answer : B

10. 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

11. 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

12. 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

13. If a 20 V potential is applied across a relay coil with 50 turns having 1 ? of resistancea the total magnetomotive producing magnetic flux in the circuit is
A. 10 Wb
B. 50 T
C. 1000 A t/m
D. 1000,t
Answer : D

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

15. 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

16. The magnetic field of a magnetized iron bar when strongly heated
A. Becomes weaker
B. Becomes stronger
C. Reverses in direction
D. is unchanged
Answer : A

17. The phenomenon by which a magnetic substance becomes a magnet when it is place near a magnet
A. Magnetic effect
B. Magnetic phenomenon
C. Magnetic induction
D. Electromagnetic induction
Answer : C

18. A magnetic material losses its ferromagnetic properties at a point called
A. Curie temperature
B. Inferred absolute temperature
C. Room temperature
D. Absolute temperature
Answer : A

19. What is the other name for dielectric strength?
A. Breakdown voltage
B. Electric intensity
C. Potential gradient
D. Dielectric constant
Answer : A

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

21. Permeance is analogous to
A. Conductance
B. Reluctance
C. Admittance
D. Resistance
Answer : A

22. When the ferromagnetic substance is inserted in a current- carrying solenoida the magnetic field is
A. Greatly decreased
B. Greatly increased
C. Slightly decreased
D. Slightly increased
Answer : B

23. A length of wire has a resistance of 10 ohms. What is the resistance of a wire of the same material three times as long and twice the cross-sectional area?
A. 30 ohms
B. 20 ohms
C. 15 ohms
D. 7 ohms
Answer : C

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

25. 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

26. Magnetic intensity is a
A. Phasor quantity
B. Physical quantity
C. Scalar quantity
D. Vector quantity
Answer : D

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

28. A good conductor has how many valence electrons?
A.
B.
C.
D.
Answer : B

29. 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

30. 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

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

32. 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

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

34. Gases whose particles are charged are known as
A. Conductors
B. Insulators
C. Gaseous Conductors
D. Plasma
Answer : D

35. The flux density in an air-cored coil is 10^-3 Wb/m^2. With a cast iron core of relative permeability 100 inserteda the flux density will become
A. 10^-3 Wb/m^2
B. 10^-2 Wb/m^2
C. 10^3 Wb/m^2
D. 0.1 Wb/m^2
Answer : D

36. What is used as the insulating material or dielectric in an electric ion
A. Oiled paper
B. Mica
C. Paraffin
D. Tit anate compound
Answer : B

37. A group of magnetically aligned atoms is called
A. Range
B. Lattice
C. Domain
D. Crystal
Answer : C

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

39. 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

40. 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

41. Another term for corona discharge.
A. Lightning
B. Sparking
C. Aurora
D. Corona Effect
Answer : C

42. 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

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

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

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

46. Referred to as the specific reluctance of a material
A. Resistivity
B. Reluctivity
C. Conductivity
D. Permeability
Answer : B

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

48. The magnetic flux through a wire loop in a magnetic field does not d
A. T he area of the loop
B. The magnitude of the field
C. The shape of the loop
D. The angle between the plane of the loop and the direction
Answer : C

49. The phenomenon that when an electric current passes through an anisotropic crystala there is an absorption or liberation of heat due to the non-uniformity in current distribution.
A. Bridgman effect
B. Corona effect
C. Dember effect
D. Destriau effect
Answer : A

50. If the magnetic material is located within a coil through which alternating current (60 Hz frequency) flowsa then __________ hysteresis loops will be formed
A.
B.
C.
D.
Answer : A