## electrical

### Magnetism and Electromagnetism MCQ Page - 1

1.
 Tesla is a unit of A Field strength B Inductance C Flux density D Flux Answer : C Explanation :
2.
 A permeable substance is one A Which is a good conductor B Which is a bad conductor C Which is a strong magnet D Through which the magnetic lines of force can pass very easily Answer : D Explanation :
3.
 The materials having low retentively are suitable for making A Weak magnet B Temporary magnet C Permanent magnet D None of the above Answer : B Explanation :
4.
 A magnetic field exits around A Iron B Copper C Aluminium D Moving charge Answer : D Explanation :
5.
 A magnet does not attract A Cobalt B Nickel C Copper D Iron Answer : C Explanation :
6.
 Aluminium and platinum are ………. Materials A Ferromagnetic B Diamagnetic C Paramagnetic D None of the above Answer : C Explanation :
7.
 Ferrites are ……. materials A Paramagnetic B Diamagnetic C Ferromagnetic D None of the above Answer : C Explanation :
8.
 Air gap has …………….. reluctance as compared to iron or steel path A Little B Lower C Higher D Zero Answer : B Explanation :
9.
 The direction of magnetic lines of force is A From south pole to north pole B From north pole to south pole C From one end of the magnet to another end D None of the above Answer : B Explanation :
10.
 Which of the following is the vector quantity? A Relative permeability B Magnetic field intensity C Flux density D Magnetic potential Answer : B Explanation :
11.
 The two conductors of a transmission line carry equal current I in opposite directions. The force on each conductor is A proportional to I B proportional to I² C proportional to distance between the conductors D  inversely proportional to I² Answer : B Explanation :
12.
 A material which is slightly repelled by a magnetic field is known as A Ferromagnetic material B Diamagnetic material C Paramagnetic material D Conducting material Answer : B Explanation :
13.
 When an iron pieces are placed in magnetic field A The magnetic lines of force will bend away from their usual paths in order to go away from the piece B The magnetic lines of force will bend away from their usual paths in order to go away in order to pass through the piece C The magnetic lines of force will not be affected D The iron piece will break Answer : B Explanation :
14.
 Fleming’s left-hand rule is used to find A Direction of magnetic field due to current carrying conductor B Direction of flux in a solenoid C Direction of force on a current D Polarity of magnetic pole Answer : C Explanation :
15.
 The ratio of intensity of magnetisation to the magnetisation force is known as A Flux density B Susceptibility C Relative permeability D None of the above Answer : B Explanation :
16.
 Magnetising steel is normal difficult because A It corrodes easily B It has high permeability C It has high specific gravity D It has low permeability Answer : D Explanation :
17.
 The left-hand rule correlates to A Current, induced e.m.f and direction of force on a conductor B Magnetic field, electric field and direction of force on a conductor C Self-induction, mutual induction and direction of force on a conductor D Current, magnetic field and direction of force on a conductor Answer : D Explanation :
18.
 The unit of relative permeability is A Hennery/meter B Hennery C Hennery/sq.m D It is dimensionless Answer : D Explanation :
19.
 A conductor of length L has current I passing through it, when it is placed parallel to a magnetic field. The force experienced by the conductor will be A Zero B BLI C B²LI D BLI² Answer : A Explanation :
20.
 The force between two long parallel conductors is inversely proportional to A Radius of conductor B Current in one conductor C Product of current in two conductor D Distance between the conductors Answer : D Explanation :
21.
 Material subjected to rapid reversal of magnetism should have A Large area of B-H loop B High permeability and low hysteresis loss C High co-ercivity and high retentivity D High co-ercivity and low density Answer : B Explanation :
22.
 Indicate which of the following material does not retain magnetism permanently A Soft iron B Stainless steel C Hardness steel D None of the above Answer : A Explanation :
23.
 The main constitute of permalloy is A Cobalt B Chromium C Nickel D Tungsten Answer : C Explanation :
24.
 The use of permanent magnet is not made in A Magnetos B Energy meter C Transformer D Loud-speaker Answer : C Explanation :
25.
 Paramagnetic materials have relative permeability A Slightly less than unity B Equal to unity C Slightly more than unity D Equal to that ferromagnetic material Answer : C Explanation :
26.
 Degaussing is the process of A Removal of magnetic impurities B Removing gases from the materials C Re-magnetising metallic parts D Demagnetising metallic parts Answer : D Explanation :
27.
 Substance which have permeability less than permeability of free space is known as A Ferromagnetic B Paramagnetic C Diamagnetic D Bipolar Answer : C Explanation :
28.
 Two infinity long parallel conductors in vacuum and separated 1 meter between centres when a current of 1 amp flows through each conductor, produce a each other a force of A 2 x 10 -2N/m B 2 x 10 -3N/m C 2 x 10 -5N/m D 2 x 10 -7N/m Answer : D Explanation :
29.
 In the left-hand rule, forefinger always represents A Voltage B Current C Magnetic field D Direction of force on the conductor Answer : C Explanation :
30.
 Which of the following is a Ferro-magnetic material? A Tungsten B Aluminium C Copper D Nickel Answer : D Explanation :
31.
 Ferrites are a sub-group of A Non-magnetic material B Ferro-magnetic materials C Paramagnetic materials D Ferri-magnetic materials Answer : D Explanation :
32.
 Gilbert is a unit of A Electromotive force B Magneto motive force C Conductance D Permittivity Answer : B Explanation :
33.
 The working of a meter is based on the use of a permanent magnet. In order to protect the meter functioning from stray magnetic field A Meter is surrounded by strong magnetic field B A soft iron shielding is used C A plastic shielding is provided D A shielding of anon-magnetic material is used Answer : B Explanation :
34.
 Reciprocal of permeability is A Reluctivity B Susceptibility C Permittivity D Conductance Answer : A Explanation :
35.
 The relative permeability is less than unity in case of A Ferromagnetic material B Ferrites C Non-ferrous materials D Diamagnetic material Answer : D Explanation :
36.
 Which of the following is the unit of magnetic flux density? A Weber B Lumens C Tesla D None of the above Answer : C Explanation :
37.
 The magnetism left in the iron after exciting field has been removed is known as A Permeance B Residual magnetism C Susceptance D Reluctance Answer : B Explanation :
38.
 Which of the following is not a unit of flux? A Maxwell B Tesla C Weber D All of the above Answer : B Explanation :
39.
 Which of the following expected to have the maximum permeability? A Brass B Copper C Zinc D Ebonite Answer : D Explanation :
40.
 1 tesla is equal to A 1 wb/mm² B 1 wb/m C 1 wb/m² D 1 m wb/m² Answer : C Explanation :
41.
 How much will be the flux density in tesla units for flux of 45µ Wb through 6 x 10-4 m² ? A 0.075 T B 0.75 T C 0.65 T D 1.5 T Answer : A Explanation :
42.
 When a magnetic is in motion relative to a coil the induced e.m.f does not depend upon A Resistance of the coil B Motion of the magnet C Numbers of turns of coil D Pole strength of the coil Answer : A Explanation :
43.
 One Maxwell is equal to A 10-8 webers B 104 webers C 10-4 webers D 108 webers Answer : D Explanation :
44.
 Super magnetic materials are composed of A Ferromagnetic particles in ferromagnetic matrix B Non-ferromagnetic particles in paramagnetic matrix C Ferromagnetic particles in anon-ferromagnetic matrix D None of the above Answer : C Explanation :
45.
 When two ends of circular uniform wire are joined to the terminals of a battery, the field at the centre of the circle A Will be zero B Will be infinite C Will depend on the amount of e.m.f applied D Will depend on the radius of the circle Answer : D Explanation :