Q.1
A electron is moving along positive x-axis. To get it move on an anticlockwise circular path in x-y plane, a magnetic filed is applied [ MPPMT 1999]
  • a) along positive y-axis
  • b) along positive z-axis
  • c)along negative y-axis
  • d)along negative z-axis
Q.2
Two wires A and B carry currents as shown in figure the magnetic interactions:
ch-16_que_no-129_img_no1.png
  • a)push I2 away from I1
  • b) pull I2 closer to I1
  • c)Turn I2 clockwise
  • d)Turn I2 counter clockwise
Q.3
The meniscus of liquid contained in one of the limbs of a narrow U tube is placed between the pole pieces of an electromagnet with the meniscus in a line with the field. the liquid is seen to rise to line. This indicates that the liquid is [ MNR 1992]
  • a) ferromagnetic
  • b) paramagnetic
  • c)diamagnetic
  • d)non-magnetic
Q.4
A circular loop of area 0.01 m2 and carrying a current of 10amp is placed perpendicular to a magnetic field of intensity of 0.1 tesla. The torque ( in Nm) acting on the loop is [ CBSE 1994]
  • a)1.1
  • b) 0.8
  • c)0.001
  • d)0.01
Q.5
A current of 10 amp is flowing in a wire of length 1.5 metre. A force of 15 N acts on it when it placed in a uniform magnetic field of 2 tesla. the angle between the magnetic field and the direction of the current is [ MPPMT 1994]
  • a) 30°
  • b) 45°
  • c) 60°
  • d) 90°
Q.6
There will be a force of repulsion between [ ISM Dhanbad 1994]
  • a)two parallel streams of electrons moving in the opposite direction
  • b) two parallel wires carrying current in the opposite direction
  • c)two parallel electron streams going in the same direction
  • d)two parallel wires carrying current in the same direction
Q.7
The magnetic field at a point at a large distance x on the axis of a current carrying circular coil of small radius is proportional to [ EAMCET 1987]
  • a) x2
  • c)x3
  • b) 1/x²
  • d)1 / x³
Q.8
A wire of length L metre carrying current i amp is bent in the form of circle. The magnitude of magnetic moment is [ MPPMT 1995]
  • a) iL2 / 4π
  • b) iL2 / 2π
  • c)4π2iL2
  • d)πL2 i
Q.9
Two straight long conductors AOB and COD are perpendicular to each other and carry currents I1 and IThe magnitude of the magnetic induction at a point P at a distance a from O in a direction perpendicular to the plane ABCD is [ MPPMT 1994]
  • a)
    ch-16_qn-136choice_img_no1.png
  • b)
    ch-16_qn-136choice_img_no2.png
  • c)
    ch-16_qn-136choice_img_no3.png
  • d)
    ch-16_qn-136choice_img_no4.png
Q.10
A current carrying rectangular coil is placed in a uniform magnetic field. In which orientation, the coil will not rotate? [ PMT 199]
  • a)the magnetic field is perpendicular to the plane of the coil
  • b) the magnetic field is parallel to the plane of coil
  • c)the magnetic field is at 45° with the plane of the coil
  • d)always in any orientation
Q.11
A charge +Q is moving upwards vertically. It enters a magnetic field directed to the north. The force on the charge will be towards [ PMT 1995]
  • a) North
  • b) South
  • c)East
  • d)West
Q.12
A current carrying circular loop is freely suspended by a long thread. The plane of the loop will point in the direction [ PMT 1995]
  • a) where ever left free
  • b) north south
  • c)east-west
  • d)at 45° with the east-west direction
Q.13
An electric charge in uniform motion produces......
  • a) an electric field only
  • b) a magnetic field only
  • c)both electric and magnetic field
  • d)no field at all
Q.14
A conducting loop of radius 'a' carries a constant current I. It is placed in a uniform magnetic field B such that B is perpendicular to the plane of loop. ThE magnetic force acting on the loop is
  • a) IaB
  • b) 4πaIB
  • c)zero
  • d)πaIB
Q.15
A straight thin conductor is bent as shown in figure. It carries a current i amp. the radius of the circular arc is r metre, then the magnetic induction at centre of the semicircular arc is [ MPPMT 1998]
ch-16_que_no-140_img_no1.png
  • a) zero
    ch-16_qn-140choice_img_no3.png
  • b) α
    ch-16_qn-140choice_img_no4.png
  • c)
  • d)
Q.16
A circular coil of radius R is placed in a uniform magnetic field such that the plane of coil is perpendicular to the magnetic field. If a current i passes through the coil, the torque acting on the coil is [ CPMT 1993]
ch-16_que_no-141_img_no1.png
  • a)BiπR2
  • b) Bi( πR2/ 2)
  • c)BiπR2 / √2
  • d)zero
Q.17
When a stationary charged particle is placed near a stream of moving charges, then the stationary charged particle [ CPMT 1993]
  • a) will experience no force
  • b) will experience a force due to electric field only
  • c)will experience a force due to magnetic field only
  • d)will experience a force due to electric and magnetic fields both
Q.18
A current i amp flows along an infinitely long straight conductor. If r metre is the perpendicular distance of a point from the lower end of the conductor, then the magnetic induction b is given by [ MPPMT 1994]
  • a)
    ch-16_qn-143choice_img_no1.png
  • b)
    ch-16_qn-143choice_img_no2.png
  • c)
    ch-16_qn-143choice_img_no3.png
  • d)
    ch-16_qn-143choice_img_no4.png
Q.19
The velocity of helium nucleus traveling in the a current path in a magnetic field is v. The velocity of the proton moving along the same path in the same magnetic field field is [ CPMT 1993]
  • a) 4v
  • b) 2v
  • c) v
  • d) v/2
Q.20
Which of the following graph shows the variation of magnetic induction B with distance r from a long wire carrying current : [ MPPMT 1999]
  • a)
    ch-16_qn-146choice_img_no1.png
  • b)
    ch-16_qn-146choice_img_no2.png
  • c)
    ch-16_qn-146choice_img_no3.png
  • d)
    ch-16_qn-146choice_img_no4.png
Q.21
A deuteron of kinetic energy 50 KeV is describing a circular orbit of radius 0.5 metre in a plane perpendicular to magnetic field B. The kinetic energy of the proton that describe a circular orbit of radius 0.5 metre in the same plane with the same B is [ CBSE 1991]
  • a) 25KeV
  • b) 50KeV
  • c)200KeV
  • d)100KeV
Q.22
A uniform magnetic field acts at right angles to the direction of motion of electrons. As a result, the electron moves in a circular path of radius 2 cm. If the speed of the electrons is doubled, then the radius of the circular path will be [ CBSE 1991]
  • a) 2.0 cm
  • b) 0.5 cm
  • c) 4.0 cm
  • d) 1.0cm
Q.23
A current loop is placed in a uniform magnetic field. The loop will experience [ CBSE 1993]
  • a)zero linear force but may experience a torque
  • b) a linear force and may experience a torque also
  • c)A linear force only
  • d)zero linear force but will necessarily experience torque
Q.24
A particle of charge q and mass m moving with velocity v along the x-axis enters the region x > 0 with uniform magnetic field B along the k direction. The particle will penetrate in this region in the x-direction up to a distance d equal to [ MPPMT 1997]
  • a) zero
  • b) mv/qB
  • c)2mv/qB
  • d)infinity
Q.25
A current of 1 amp is passed through a straight wire of length 2.0 metres. The magnetic field at a point in air at distance of 3 metres from either end of wire and lying on the axis of wire will be [ MPPMT 1995]
  • a) µo / 2π
  • b) µo / 4π
  • c)µo / 8π
  • d)zero
Q.26
A wire of fixed length L can be formed into many circular loops of varying radii r depending on the number of turns n. The loop so formed is carrying a current and is so placed normally in a uniform magnetic field B. In order that the torque on the circular loop formed be maximum, the number of turns n must be equal
  • a) 1
  • b) 4
  • c) 8
  • d) ∞
Q.27
A proton and an alpha particle enter in a uniform magnetic field with same velocity. The period of rotation of the alpha particle will be [ mPPMT 1990]
  • a)four times that of proton
  • b) two times that of proton
  • c)three times that of proton
  • d)same as that of the proton
Q.28
An electron of charge e is going around in an orbit of radius R metres in hydrogen atom with velocity v m/s. The magnetic flux density associated with it at its centre is [ CBSE 1993]
  • a)
    ch-16_qn-154choice_img_no1.png
  • b)
    ch-16_qn-154choice_img_no2.png
  • c)
    ch-16_qn-154choice_img_no3.png
  • d)
    ch-16_qn-154choice_img_no4.png
Q.29
H+, He++ and O++ all having same kinetic energy pass through a region in which there is a uniform magnetic filed perpendicular to their velocity. The masses of H+,He++ and O++ are 1 amu. 4 amu and 16 amu respectively. Then [ IIT 1994]
  • a) H+ will be deflected most
  • b) O++ will be deflected most
  • c)He + and O++ will deflect equally
  • d)All will be deflected equally
Q.30
Weber ampere per meter is equal to [ MPPMT 1990]
  • a) joule
  • b) newton
  • c) henry
  • d) watt
0 h : 0 m : 1 s