10 eV electron is circulating in a plane at right angle to a uniform field of magnetic induction 10-1 Wb/m² (1G). The orbital radius of electron is:
1.12 cm
2.16 cm
3.11 cm
4.18 cm
Posted Date:-2021-12-16 11:50:13
A charge + q is sent through a magnetic field. The force acting on it is maximum w hen the angle between the direction of motion of the charged particle and the magnetic field :
1.0°
2.45°
3.90°
4.180°
Posted Date:-2021-12-16 11:40:58
A current carring coil is placed in a uniform magnetic field. If the coil turns through an angle θ, then the torque is directly proportional to:
1. sin θ
2.cos θ
3.cot θ
4.tan θ
Posted Date:-2021-12-16 11:11:04
A current carrying power line carries current from west to east. Then the direction of the magnetic field 2 m above it is :
1.west to east
2. south to north
3.north to south
4.None of the above
Posted Date:-2021-12-16 11:38:01
A cyclotron can be used to produce high energy:
1.neutrons
2.deutrons
3.β particles
4.α partifcles
Posted Date:-2021-12-16 11:50:58
A wire of length 2 metre carries a current 1 ampere, is bent to form a circle. The magnetic moment of the coil is :
1. 2Ï€
2.Ï€/2
3.Ï€/4
4.1/Ï€
Posted Date:-2021-12-16 11:41:56
According to Gauss’s theorem in magnetism, surface integral of magnetic field intensity over a surface (closed or open) is always:
1.-1
2.1
3.0
4.infinity
Posted Date:-2021-12-16 11:48:48
Circular loop of radius 0.0157 m carries a current 2 A. The magnetic field at the centre of the loop is :
1.1.57 × 10-3Wb/m²
2.8.0 × 10-5 Wb/m²
3.2.0 × 10-3 Wb/m²
4.3.l4 × 10-1 Wb/m²
Posted Date:-2021-12-16 11:17:43
Earth’s magnetism was discovered by:
1.Gauss
2.Oersted
3.Ampere
4.Gilbert
Posted Date:-2021-12-16 11:48:03
Isoclinic lines are the lines joining places with :
1.equal dip
2.equal declination
3.equal dip and declination
4.None of the above
Posted Date:-2021-12-16 11:45:48
same everywhere
1. same everywhere
2. inversely proportional to the distance
3.directly proportional to the distance
4.None of the above
Posted Date:-2021-12-16 11:33:30
Tesla is a unit of:
1. electric flux
2. magnetic flux
3.magnetic field
4.electric field
Posted Date:-2021-12-16 11:49:32
The current sensitibility of a moving coil galanometer increases with decrease in:
1.magnetic field
2.area of a coil
3.number of turns
4.None of the above
Posted Date:-2021-12-16 11:10:00
The force between two parallel current carrying conductors is F. If the current in each conductor is doubled, then the force between them becomes :
1.4F
2.2F
3.F
4.F/4
Posted Date:-2021-12-16 11:39:03
The magnetic field of a given length of a ware for single turn coil at its centre is B. Then.its value for two turns of coil will be :
1.B/4
2.B/2
3.4B
4.2B
Posted Date:-2021-12-16 11:43:09
The most suitable metal for making permanent magnets is :
1.iron
2.steel
3.copper
4.aluminium
Posted Date:-2021-12-16 11:46:31
The permeability of a paramagnetic substance is:
1. very large
2. small but more than unity
3.less than unity
4.negative
Posted Date:-2021-12-16 11:14:07
The radius of the trajectory of a charged particle in a uniform magnetic field is proportional to the:
1.charge on the particle
2.energy of the particle
3.momentum of the particle
4.All the above
Posted Date:-2021-12-16 11:51:40
The sensitivity of a tangent galvanometer can be increased by increasing:
1.the radius of the coil
2.the external magnetic field
3. the number of turns of the coil
4.all the above
Posted Date:-2021-12-16 11:12:36
The SI unit of magnetic dipole moment is’
1.Ampere
2.Ampere metre²
3.Tesla
4.None of the above
Posted Date:-2021-12-16 11:47:23
The strength of the magnetic field around an infinite current carrying conductor is :
1.same everywhere
2.inversely proportional to the distance
3.directly proportional to the distance
4.None of the above
Posted Date:-2021-12-16 11:29:07
To convert galvanometer into voltmeter one should connect :
1.high resistance in series with galvanometer
2.low resistance in series with galvanometer
3.high resistance in parallel with galvanometer
4. low resistance in parallel with galvanometer
Posted Date:-2021-12-16 11:45:05
What happens to the magnetic field at the centre of a circular current carrying coil if we double the radius of the coil keeping the current unchanged?
1.halved
2.doubled
3.quadrupled
4.remains unchanged
Posted Date:-2021-12-16 11:18:45
What is the angle of dip at the magnetic poles ?
1. 30°
2.0°
3.45°
4.None of the above
Posted Date:-2021-12-16 11:16:16
When charged particle enters-a uniform magnetic field, its K.E.:
1. remains constant
2.increases
3.decreases
4.becomes zero
Posted Date:-2021-12-16 11:44:06
When we double the radius of a coil keeping the current through it unchanged, what happens to the magnetic field directed along its axis at far off points?
1.halved
2.doubled
3.quadrupled
4.remains unchanged
Posted Date:-2021-12-16 11:21:09
Which of the following is not a unit of magnetic induction?
1.gauss
2.tesla
3.oersted
4.weber/metre²
Posted Date:-2021-12-16 11:40:03
Which of the following shows that the earth behaves as a magnet?
1.Repulsion between like poles .
2.Attraction between unlike poles
3.Null points in the magnetic field of a bar magnet
4.No existence of isolated magnetic poles
Posted Date:-2021-12-16 11:15:30