1000+ Electricity Fundamentals MCQ for GATE [Solved]

1. 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

2. One of the common application of an air- cored choke.
A. Radio frequency
B. Audio frequency
C. Power supply
D. Power transformer
Answer : A

3. 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

4. Who discovered that a current-carrying conductor would move when placed in a magnetic field?
A. Michael Faraday
B. Andre Ampere
C. Hans Christian Oersted
D. Gustav Robert Kirchhoff
Answer : A

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

6. The B-H curve of ________ is not a straight line.
A. air
B. wood
C. silicon steel
D. soft iron
Answer : D

7. Temporary magnets are commonly employed in
A. electric instruments
B. motors
C. moving coils loudspeakers
D. magnetos
Answer : B

8. 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

9. One weber of flux is equal to _______ magnetic lines of force.
A. 10^6
B. 10^10
C. 4 × 10^7
D. 10^8
Answer : D

10. If a magnetic flux cuts across 200 turns at a rate of 2Wb/sa the induced voltage according to Faraday's law is about
A. 400 V
B. 100 V
C. 200 V
D. 600 V
Answer : A

11. 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

12. 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

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

14. The force between two magnetic poles varies with the distance between them. The variation is ______ to the square of that distance.
A. Equal
B. Greater than
C. Directly proportional
D. Inversely proportional
Answer : D

15. The ratio between the intensity of magnetization produced in a substance to the magnetizing force producing it
A. Magnetic Reluctivity
B. Magnetic Resistivity
C. Magnetic susceptibility
D. Magnetic conductivity
Answer : C

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

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

18. A law stating that the magnetic susceptibilities of most paramagnetic substances are inversely proportional to their absolute temperatures.
A. Curie's Law
B. Child's Law
C. CR Law
D. Curie-Weiss Law
Answer : A

19. When the current flowsa the magnetic field ��. conductor is in what direction?
A. The same as the current direction
B. Opposite the current direction
C. Omnidirectional
D. In the direction determined by the left hand rule
Answer : D

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

21. Which of the following is a paramagnetic material?
A. Carbon
B. Copper
C. Bismuth
D. Oxygen
Answer : D

22. At/m is a unit of
A. mmf
B. magnetic force
C. reluctance
D. magnetic flux density
Answer : B

23. The relative permeability of a magnetic material is 10^5. What is its permeability?
A. 4 × 10^5 H/m
B. 4 × 10^-12 H/m
C. 4× 10^-2 H/m
D. 4 × 10^7H/m
Answer : C

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

25. If the value of 0 a conductor is 1/234 per oCa then the value of 18is
A. 1/218 per oC
B. 1/252 peroC
C. 1/272 per oC
D. 1/273 per oC
Answer : B

26. 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

27. 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

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

29. Calculate the flux density that will be produced by the field intensity of 2000 a. t/m for a permeability of 126 x 10^-6 T/A.t/m
A. 0.252 G
B. 0.252 x 10^-2 T
C. 0.252 T
D. 0.252 x 10^-2 G
Answer : C

30. The magnetic materials should have a large hysteresis loss for one of the following applications.
A. Transformers
B. ACmotors
C. Permanent Magnets
D. DC generators
Answer : C

31. 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

32. What bond is formed when electrons in the outermost energy orbits of the atoms are shared between two or more electrons?
A. Ionic
B. Covalent
C. Metallic
D. Van der Waals
Answer : B

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

34. 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

35. The tiniest element of matter
A. Atom
B. Proton
C. Electron
D. Neutron
Answer : A

36. 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

37. What is the SI unit of reluctance?
A. At
B. At/m
C. N/Wb
D. At/Wb
Answer : D

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

39. 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

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

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

42. There are how many compounds available in nature?
A.
B.
C. 300a000
D. Unlimited
Answer : D

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

44. 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

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

46. A magnetic field is
A. The current flow through space around a permanent magnet
B. The force set up when current flows through a conductor
C. The force that drives current through a resistor
D. The force between the plates of a charged capacitor
Answer : B

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

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

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

50. 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