ELECTRICITY AND MAGNETISM FUNDAMENTALS Multiple Choice Questions Part 3

1 The current of electric circuit is analogous to which quantity of a magnetic circuit
Mmf
Flux
Flux density
Reluctivity

2 What is the diameter of an atom?

3 Defined as a closed path in which magnetic induction or flux flows
Electric circuit
Magnetic circuit
Electronic circuit
Electromagnetic circuit

4 The force which set ups or tends to set up magnetic flux in a magnetic circuit
Dynamic force
Electromotive force
Potential  difference
Magnetomotive force

5 Referred to as the specific reluctance of a material
Resistivity
Reluctivity
Conductivity
Permeability

6 The property of a material which opposes the creation of magnetic flux in it
Resistance
Reluctance
Permanence
Conductance

7 It is the reciprocal of reluctance and implies the case of readiness with which magnetic flux is developed.
Resistance
Conductance
Permanence
Inductance

8 The ability of a material to conduct magnetic flux through it.
Permittivity
Reluctivity
Conductivity
Permeability

9 The ratio of the permeability of material to the permiabiity of air or vacuum.
Relative Permittivity
Relative permeability
Relative conductivity
Relative Reluctivity

10 Permeance is analogous to
Reluctance
Resistance
Conductance

11 The property of magnetic materials of retaining magnetism after withdrawal of the magnetizing force is known as
Retentivity
Reluctivity
Resistivity
Conductivity

12 The quantity of magnetism retained by a magnetic material after withdrawal of the magnetizing force is called
Leftover magnetism
Hysteresis
Residual magnetism
Coercivity

13 The amount of magnetizing force to counter balance the residual magnetism of a
magnetic material is referred to as
Reluctivity
Susceptivity
Coercivity
Retentivity

14 The ratio of the total flux (flux in iron path) to the useful flux (flux in air gap)
Leakage flux
Leakage current
Leakage coefficient
Leakage factor

15 Defined as the number of lines per unit area through any substance in a plane at right angles to the lines of force
Flux
Flux lines
Flux density
Flux intensity

16 Defined as the flux density produced in it due to its own induced magnetism
Magnetic field intensity
Electric field intensity
Intensity magnetization
Electromagnetic field intensity

17 The force acting on a unit n- pole placed at that point is called.
Electric field intensity
Electromagnetic field intensity
Magnetic field intensity
Intensity magnetization

18 The  force  between  two  charges placed  a given distance apart  as the relative
permittivity of the medium is increased.
increases
decreases
remains unchanged
becomes infinite

19 A test charge means a charge of
-1 C
1 electron
⦁ +1 C
⦁ -20 C

20 Electric lines of force leave or enter the charge surface at an angle of
30o
45o
90o
depending upon the angle of launch and entry

21 Electric field intensity is a  .
scalar
phasor
vector
variable

22 All magnetic field originates from.
Iron atoms
Magnetic domain
Moving electric charge
Permanent magnets

23 The magnetic field of a magnetized iron bar when strongly heated.
Becomes stronger
Becomes weaker
Reverses in direction
is unchanged

24 The induced emf in a wire loop that is moved parallel to a uniform magnetic field is.
Dependent on the area of the loop
Zero
Dependent on the shape of the loop
Dependent on the magnitude of the field

25 When a wire loop is rotated in a magnetic field the direction of the induced emf changes
one in every ______ revolution.
1/3
1/2
1/4
2/3

26 Steel is hard to magnetize because of its.
High permeability
Low permeability
High density
High retentivity

27 The force between two magnetic poles varies with the distance between them. The variation is  to the square of that distance.
Equal
Greater than
Directly proportional
Inversely proportional

28 A magnetic material losses its ferromagnetic properties at a point called.
Inferred absolute temperature
Curie temperature
Room temperature
Absolute temperature

29 The tiniest element of matter.
Proton
Atom
Electron
Neutron

30 All matters (gas, liquid and solid) are composed of
Neutrons
Particles
Electrons
Atoms

31 The uncharged particles which have no effect on its atomic charge.
Nucleons
Electrons
Protons
Neutrons

32 The K shell or the first shell has how many permissible number of orbiting electrons?
1
2
3
4

33 Germanium atom has  protons and  electrons.
⦁  32, 42
⦁  42, 32
⦁  32, 32
⦁  34, 34

34 Which of the following electric quantities is vector in character?
Charge
Energy
Field
Potential Difference

35 The customary energy unit in atomic and nuclear physics is
Joule
Volt- coulomb
electron-volt
Walt- second

36 An alloy of 22 percent iron and 78 per cent nickel.
Alnico
Constantan
Permalloy
Manganin

37 Which element has four valence electrons?
Conductor
Insulator
Semiconductor
Semi- insulator

38 A negative ion results when an atom gains an additional
Electron
Proton
Neutron
Atom

39 An atom or a group of atoms that carries a net electric charge.
Positive ion
Negative ion
Ion
Electron

40 The evaporation of electrons from a heated surface is called
Convection
Thermionic emission
Conduction

41 Mmf in a magnetic circuit corresponds to _____ in an electric circuit.
Voltage drop
Electric Field Intensity
Emf

42 The electric potential across part AB of a circuit is 5 V; point A being at higher
potential. If a charge of 5 C moves from A to B, then energy released as
5 joules
25 joules
10 joules
100 joules

43 What is used as the insulating material or dielectric in an electric ion?
Oiled paper
Mica
Paraffin
Titanate compound

44 What is used as the dielectric material in high voltage transformers?
Mica
Paraffin
Porcelain
Oiled paper

45 Which of the following is used by permanent magnets as the magnetic material?
Iron
Nickel
Soft steel
Hardened steel

46 Which of the following is used by temporary magnets as the magnetic material?
Hardened steel
Cobalt steel
Soft iron
Tungsten steel

47 Permanent magnets can be found in
electric bells
earphones
relays
dynamic loudspeakers

48 Which of the following materials has permeability slightly less than that of free space?
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic

49 Materials whose permeabilities are slightly greater than that of free space.
Non- magnetic
Ferromagnetic
Diamagnetic
Paramagnetic

50 Materials that have very high permeabilities (hundreds and even thousands times of that
of free space)
Paramagnetic
Non- magnetic
Ferromagnetic
Diamagnetic