Electricity Fundamentals MCQ Solved Paper for IBPS PO

1. What is the unit of reluctance?
A. Maxwell
B. Gauss
C. At/Wb
D. Weber
Answer : C

2. Defined as a closed path in which magnetic induction or flux flows
A. Electric circuit
B. Magnetic circuit
C. Electronic circuit
D. Electromagnetic circuit
Answer : B

3. What determines the value of the temperature coefficient of resistance of a material?
A. length
B. cross-sectional area
C. volume
D. nature and temperature
Answer : D

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

5. 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

6. 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

7. Electromotive force in a circuit
A. causes free electrons to flow
B. increases the circuit resistance
C. maintains circuit resistance
D. is needed to make the circuit complete
Answer : A

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

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

10. 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

11. Which of the following is used by temporary magnets as the magnetic material?
A. Hardened steel
B. Cobalt steel
C. Soft iron
D. Tungsten steel
Answer : C

12. 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

13. Define as that pole which when placed in air from a similar and equal pole repels it with a force of newtons
A. North pole
B. South pole
C. Unit pole
D. Magnetic pole
Answer : C

14. 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

15. Why is it that the magnitude of magnetomotive force required for air gap is much greater than that required for iron part of a magnetic circuit?
A. Because air is a gas
B. Because air has the highest relative permeability
C. Because air is a conductor of magnetic flux
D. Because air has the lowest relative permeability
Answer : D

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

17. An effect which is generally used in the gausameter to measure flux density.
A. Skin effect
B. Magnetic effect
C. Hall effect
D. Flywheel effect
Answer : C

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. 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

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

21. The reluctance of a magnetic circuit is not dependent on which of the following?
A. Number of turns of coil
B. Magnetomotive force
C. Flux density in the circuit
D. Current in the coil
Answer : C

22. Ohm's law can be used only to a _____ circuit or component.
A. Unilateral
B. Exponential
C. Trivalent
D. Linear
Answer : D

23. The evaporation of electrons from a heated surface is called
A. Radiation
B. Convection
C. Thermionic emission
D. Conduction
Answer : C

24. ______ is an electromagnet with its core in the form of a close magnetic ring.
A. S olenoid
B. Paraboloid
C. Toroid
D. Cycloid
Answer : C

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

26. Formed when there exist distant electronic interactions between (opposite) charges present in the neighboring atoms or molecules.
A. Ionic bond
B. Covalent bond
C. Metallic bond
D. Van der Waals bond
Answer : D

27. 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

28. The reluctance of a magnetic circuit varies with
A. length × area
B. area � length
C. length � area
D. length + area
Answer : C

29. 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

30. The force which set ups or tends to set up magnetic flux in a magnetic circuit
A. Dynamic force
B. Electromotive force
C. Potential difference
D. Magnetomotive force
Answer : D

31. 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

32. When a current carrying conductor is placed in a magnetic fielda the maximum force will act on the conductor when the conductor is at an angle of _______ to the magnetic field.
A. 45o
B. 60o
C. 30o
D. 90o
Answer : D

33. 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

34. The phenomenon by which a subtracts pieces of iron
A. Magnetism
B. Electromagnetism
C. Naturalism
D. Materialism
Answer : A

35. 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

36. Hysteresis refers to the ______ between flux density of the material and the magnetizing force applied.
A. Leading effect
B. Ratio
C. Equality
D. Lagging effect
Answer : D

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

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

39. If you hold the conductor with right hand so that the stretched thumb points in the direction of the currenta then encircling fingers will give the direction of magnetic lines of force round the conductor. This is known as
A. Left hand cork screw rule
B. Right hand cork screw rule
C. Left hand rule
D. Right hand rule
Answer : D

40. 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

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

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

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

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

45. Used to maintain strength of magnetic field
A. Container
B. Air gap
C. Keeper
D. S ource
Answer : C

46. 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

47. 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

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

49. 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

50. The core of a transformer heats up when its primary is fed from an ac source because of
A. permeability
B. ferromagnetism
C. reluctance of core
D. hysteresis loss
Answer : D