100 Important Magnetism and Electromagnetism MCQ Question and Answer | PDF Free Download
1.When two ends of circular uniform wire are joined to the terminals of a battery, the field at the centre of the circle
- AWill be zero
- BWill be infinite
- CWill depend on the amount of e.m.f applied
- DWill depend on the radius of the circle
2.Susceptibility is positive for
- ANon-magnetic substance
- BDiamagnetic substance
- CFerromagnetic substance
- DNone of the above
3.Two long parallel conductors carry 100 A. if the conductors are separated by 20 mm, the force per meter of length of each conductor will be
- A100 N
- B10 N
- C1 N
- D0.1 N
4.The tubes of force within the magnetic materials are known as
- AElectric flux
- BLines of force
- CTubes of induction
- DNone of the above
5.The unit of flux is same as that of
- AReluctance
- BResistance
- CPermeance
- DPole strength
7.The Biot-savart's law is a general modification of
- AKirchhoff?s law
- BLenz?s law
- CAmpere?s law
- DFaraday?s law
8.The most effective and quickest way of making magnet from soft iron is by
- APlacing it inside a coil carrying current
- BInduction
- CThe use of permanent magnet
- DRubbing with another magnet
9.The commonly used material for shielding or screening magnetism is
- ACopper
- Baluminium
- CSoft iron
- DBrass
10.If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity
- ALess than that of disc but in opposite direction
- BEqual to that of disc and in the same direction
- CEqual to that of disc and in the same direction
- DLess than that of disc and in the same direction
11.A permanent magnet
- AAttracts some substances and repels other
- BAttracts all paramagnetic substance and repels other
- CAttracts only ferromagnetic substances
- DAttracts ferromagnetic substances and repels other
12.The retentivity ( a property) of material is useful for construction of
- A permanent magnets
- BTransformers
- CNon-magnetic substances
- DElectromagnets
13.The relative permeability of ???? a material is not constant
- ADiamagnetic
- BParamagnetic
- CFerromagnetic
- DInsulating
14.The ???. Materials are a bit inferior conductors of magnetic flux than air.
- AFerromagnetic
- BParamagnetic
- CDiamagnetic
- DDielectric
15.Hysteresis loop in case of magnetically hard materials is more ??.. in shape as compared to magnetically soft materials.
- ACircular
- BTriangular
- CRectangular
- DNone of the above
16.A rectangular magnet of magnetic moment M is cut into two pieces of same length, the magnetic moment of each piece will be
- AM
- BM/2
- C2M
- DM/4
17.A keeper is used to
- AChange in direction of magnetic lines
- BAmplify flux
- CRestore lost flux
- DProvide a close path for flux
18.Magnetic moment is a
- APole strength
- BUniversal constant
- CScalar quantity
- DVector quantity
19.The change of cross-sectional area of conductor in magnetic field will affect the
- AReluctance of conductor
- BResistance of conductor
- C(a) and (b) both in the same way
- DNone of the above
20.The uniform magnetic field is
- AThe field of a set of parallel conductor
- BThe field of a single conductor
- CThe field in which all lines of magnetic flux are parallel and equidistant
- DNone of the above