A coil of 100 turns and area 0.5 m2 has its plane perpendicular to a uniform magnetic field of induction 0.2m Wb/ m2.Then magnetic flux through the coil is
1.zero
2.0.1 Wb
3.1 Wb
4.10 Wb
A current of 1.5A flows through the coil of 5 turns of a tangent galvanometer having a diameter 0.3m. If the deflection of the needle at its centre is 45� then the horizontal intensity of earths field at that place is
1.250 A-turn/m250 A-turn/m
2.25 A-turn/m
3.2.5 A-turn/m
4.2500 A-turn/m
A current of 1A flowing through a property arranged tangent galvanometer produces a deflection of 30� in the needle. The current required to produce a deflection of 60� is
1.2A
2.1.5A
3.3A
4.4A
A magnetic needle suspended at a place having two magnetic fields comes to rest when
1.two fields are at right angle
2.one of the field coincides with earths magnetic field
3.couples acting on the needle are equal and opposite
4.the needle is around 45�
A tangent galvanometer is an absolute instrument because
1.it uses a small magnetic needle
2.it measures earths magnetic field
3.it is sensitive around 45�
4.it does not take the help of other instruments for calibration
By tangent law the field due to the magnet is
1.B
2.tan ?
3.B tan ?
4.None of them
During the initial adjustment the magnetic needle of the deflection magnetometer in Tan B position
1.position East � West direction
2.is perpendicular to magnetic meridian
3.points North � South direction
4.shows 0-0 on the graduated scale
During the initial adjustment the pointer of the deflection magnetometer in TanA position.
1.points East � West direction
2.points North � South direction
3.is perpendicular to magnetic meridian
4.is along the arms
For a short magnet placed along the arms of deflection magnetometer in TanA position
1.2M/d3 tan ? ? 10-7 = B
2.M/B ? 107 = d3 tan ?
3.M = d3 B tan ? ? 107
4.M/B = d3/2 . tan ? ? 107
For a short placed across the arms of deflection magnetometer in tan B position
1.M/B = d3/2 .tan ? ? 107
2.M/B = 10-7 d3 tan ?
3.M/B = d3 tan ? ? 107
4.M/B = 10-7.d3/2 .tan ?
If the field at the centre of a coil of radius 8 cm having 80 turns is 200 A-turn/m then the current passing through it is
1.4:00 AM
2.40 A
3.0.4 A
4.400 A
If the reduction factor of a tangent galvanometer is 900mA then the current that produces a deflection of 30� in it is
1.400mA
2.520A
3.450A
4.520mA
in a coil of radius r and having n turns the intensity of magnetic field produced by current of I A is
1.H = n I/2r2
2.H = n I/2r
3.H = 2r/n I
4.H = n I/2
In Tan A position a short bar magnet placed at a distance of 30 cm from the mid-point of the needle produces a deflection of 45�. When another magnet is placed at the same distance it produces a deflection of 30�. Then the ratio of their magnetic moments is
1.1.1
2.1.72
3.5.1732
4.1.732
In Tan A position of equal distance method of comparing the magnetic moments of bar magnets the ratio of their moments is given by
1.M1/M2 = (d2+l12)2 tan ?1/ (d2+l22)2 tan ?2
2.M1/M2 = (d2+l12)3/2 tan ?1/ (d2+l22)3/2 tan ?2
3.M1/M2 = (d2-l12)2 tan ?1/ (d2-l22)2 tan ?2
4.M1/M2 = (d2-l12)3/2 tan ?1/ (d2-l22)3/2 tan ?2
In Tan A position of null deflection method of comparing the magnetic moments of bar magnets the ratio of their moments is given by
1.M1/M2 = (d12-l12)2 d2/ (d12-l22)2 d1
2.M1/M2 = (d12-l12)2 d1/ (d12-l22)2 d2
3.M1/M2 = (d12+l12)2 d1/ (d12+l22)2 d2
4.M1/M2 = (d12+l12)2 d2/ (d22-l22)2 d1
In Tan B position of equal distance method of comparing magnetic moments of bar magnets the ratio of their moments is given be
1.M1/M2 = (d2+l22)3/2 tan ?1/ (d2+l12)3/2 tan ?2
2.M1/M2 = (d2+l12)3/2 tan ?1/ (d2+l22)3/2 tan ?2
3.M1/M2 = (d2-l12)2 tan ?1/ (d2+l22)2 tan ?2
4.M1/M2 = (d2+l12)2 tan ?1/ (d2+l22)2 tan ?2
In Tan B position of null deflection method of comparing the magnetic moments of bar magnets the ratio of their moments is given by
1.M1/M2 = (d12+l12)3/2/ (d22+l22)3/2
2.M1/M2 = (d12-l12)3/2/ (d22-l22)3/2
3.M1/M2 = (d22+l22)3/2/ (d12+l12)3/2
4.M1/M2 = (d22-l22)3/2/ (d12-l12)3/2
In TanA position the arms of the magnetometer are kept
1.parallel to the magnetic meridian
2.along the magnetic meridian
3.perpendicular to the magnetic meridian
4.along the equator
In tangent galvanometer experiment the plane of the coil should be adjusted to be along the
1.magnetic axis
2.equator
3.magnetic meridian
4.East-West direction
Magnetic intensity due to a bar magnet of length 2l and pole strength m at an equatorial point at a distance d from the mid-point is
1.�0/4? . Md/(d2+l2 )3/2
2.�0/4? . 2Md/(d2+l2 )3/2
3.�0/4? . M/(d2+l2 )3/2 parallel to axis directed N ?S
4.�0/4? . M/(d2+l2 )3/2 parallel to axis directed S ?N
Plane of the tangent galvanometer is set along the magnetic meridian because in that case the field due to current is
1.zero
2.parallel to the magnetic meridian
3.perpendicular to the magnetic meridian
4.infinity
Tangent galvanometer works on the principle of
1.Biot-Savarts law
2.Amperes law
3.Coulombs law
4.Tangent law
Tangent law is used
1.when two uniform and mutually perpendicular magnetic fields are present
2.when two uniform and parallel magnetic fields are present
3.when two magnetic fields are present
4.when horizontal component of the earths magnetic field is present
The circular compass box of a tangent galvanometer has graduations
1.from 0 to 360�
2.from 0� to 180�
3.from 0� to 90�
4.from 0� to 45�
The deflection magnetometer is constructed such that the centre of the magnetic needle
1.is at the centre of the compass box
2.is at the centre of the plate form
3.is at the centre of the magnetic meridian
4.coinides with the zeros of the graduations an the arms
The deflection magnetometer works on the principle of
1.Coulombs law
2.Biot-savart law
3.Tangent law
4.Ampere law
The deflection of magnetic needle produced by two short magnets are 30� and 60� respectively when the magnets are placed at the same distance along the ration of their magnetic moments is
1.1:02
2.2:01
3.3:01
4.1:03
The field at the centre of a coil of radius 16 cm having 10 turns and carrying a current of 8 A is
1.25 A-turns/m
2.2.5 A-turns/m
3.80?10-2 A-turns/m
The magnetic field along the axis of a bar magnet is
1.B = �0/4? . 2Md/(d2-l2)3/2
2.B = �0/4? . M/(d2+l2)3/2
3.B = �0/4? . 2Md/(d2-l2)2
4.B = �0/4? . M/(d2+l2)2
The magnetic needle of a tangent galvanometer is kept small because the magnetic field is
1.very small
2.very large
3.considered to be uniform over a small area
4.such that it is convenient to handle small needle
The plane of the compass box of a tangent galvanometer is
1.along the magnetic meridian
2.parallel to the turn table
3.parallel to the plane of the coil
4.vertical
The reduction factor k of a tangent galvanometer is
1.2nHh
2.2Hh/r
3.2rHh/n
4.2nrHh
The tangent galvanometer is more sensitive when the deflection is around
1.0�
2.30�
3.90�
4.45�
The tangent galvanometer is used to determine
1.potential difference
2.deflection
3.resistance
4.current
the two turn coil of a tangent galvanometer
1.is used to produce a magnetic field
2.is used to measure currents of low value
3.is used to measure currents of high value
4.is made with thin wire