22.The direction of magnetic field is the direction along which
1.a tiny bar magnet moves
2.an isolated south pole moves
3.an isolated north pole moves
4.a unit positive charge moves
A freely suspended magnet will always come to rest in the direction
1.East-North
2.North-West
3.North-South
4.South-West
A line of force in a magnetic field
1.is a line joining the poles
2.is a path along which an isolated charge moves
3.is a path along which a short bar magnet moves
4.is a path along which an isolated north pole moves
A uniform magnetic field
1.is produced by a bar magnet
2.is produced by an isolated north pole
3.has parallel flux lines
4.produces no force on a north pole
Ampere-meter is the unit of
1.magnetic moment
2.pole strength
3.electric potential
4.magnetic potential
Force between two identical magnets is proportional to
1.m/d
2.m2/d
3.m/d2
4.m2/d2
Force of the attraction between two poles placed in vacuum
1.decreases as the pole strength increases
2.increases with decrease in distance
3.decreases with decrease in distance
4.increases with decrease in pole strength
� indicates the property of
1.a dielectric
2.a conductor
3.a magnetic material
4.an insulator
� is the symbol for
1.permittivity
2.permeability
3.conductivity
4.resistivity
One tesla is equivalent to
1.weber
2.weber/metre2
3.amp-metre
4.amp/metre
The dimension of �r is
1.ML0 T -1
2.LT -1
3.HM -1
4.nil
The distance between the poles of a magnet is called
1.magnetic axis
2.magnetic moments
3.length of the magnet
4.magnetic length
The flux density is
1.a scalar quantity
2.is a vector quantity
3.the magnetic moment per unit volume
4.the dipoles per unit volume
The force experienced by a magnet of pole strength m in a uniform magnetic field of strength H is
1.mH
2.m/H
3.H/m
4.mWb
The intensity of magnetic field is the force acting on
1.a short bar magnet
2.a long bar magnet
3.a unit north pole
4.a unit south pole
The magnetic axis of a magnet is
1.perpendicular to the length of the magnet
2.along the line joining the poles
3.the direction of zero magnetic flux
4.a line of zero moment
The magnetic flux
1.is a scalar quantity
2.is a vector quantity
3.denotes the amount of the force on a north pole
4.is the magnetic moment of a bar magnet
The north pole of the earths magnetic field
1.is at the centre of the earth
2.lies along the equatorial line
3.lies in the northern hemisphere
4.lies in the southern hemisphere
The permeability of free space is
1.1 H/m
2.0
3.4? ? 10-7 H/m
4.4? ? 107 H/m
The ratio of the flux density to the magnetic field strength in a medium is its
1.intensity of magnetization
2.susceptibility
3.relative permeability
4.permeability
The relationship between magnetic flux and magnetic induction B is
1.? = B/A
2.B = A/?
3.B = ? A
4.B = ?/A
The relationship between relative permeability of a medium and permeability of free space is
1.�r = �r ? �0
2.� = �0 �r
3.�r = �0 / �
4.� = �0 / �r
The relationship between the magnetic induction B and the intensity of magnetic field H is
1.�0 = H/B
2.B = �0 H
3.H = �0 B
4.�0 = HB
The south pole of the earths magnetic field
1.is at the centre of the earth
2.lies along the equatorial line
3.lies in the northern hemisphere
4.lies in the southern hemisphere
The total number of lines of induction crossing any area is known as
1.magnetic induction
2.magnetic flux
3.magnetic field
4.mutual induction
The unit of intensity of magnetic field is
1.weber/metre2
2.weber/metre
3.ampere-metre2
4.ampere /metre
The unit of magnetic flux is
1.weber
2.tesla
3.weber-metre
4.ampere-metre
The unit of permeability is
1.H
2.Hm
3.H/m
4.Wb
The unit of pole strength is
1.Am
2.A/m
3.Wbm
4.Wb/m
The value of the relative permeability of air is
1.4? ? 10-7
2.0
3.-1
4.1
ttractive force exists between
1.two south poles
2.two north poles
3.poles of the same magnet
4.one north pole and one south pole
When a magnet is dipped in iron filings the fillings
1.cling throughout the magnet
2.cling to the magnet at the ends only
3.cling to the magnet at its center only
4.do not cling to the magnet