BITSAT SERIES Physics
Magnetic Field
29 previous year questions.
Volume: 29 Ques
Yield: High
High-Yield Trend
3
2023 2
2021 2
2020 3
2019 2
2018 2
2017 2
2016 4
2015 1
2014 2
2013 1
2012 1
2011 1
2010 1
2009 1
2008 Chapter Questions 29 MCQs
01
PYQ 2007
medium
physics ID: bitsat-2
The cyclotron frequency of an electron grating in a magnetic field of is approximately
1
28 MHZ
2
280 MHZ
3
2.8 GHZ
4
28 GHZ
02
PYQ 2008
medium
physics ID: bitsat-2
Two concentric coils of turns each are placed in the same plane. Their radii are and and carry and . current respectively in opposite directions. The magnetic induction (in tesla) at the center is
1
2
3
4
03
PYQ 2009
medium
physics ID: bitsat-2
An infinitely long straight conductor is bent into the shape as shown below. It carries a current of ampere and the radius of the circular loop is metre. Then, the magnitude of magnetic induction at the centre of the circular loop is -
1
2
3
4
04
PYQ 2010
medium
physics ID: bitsat-2
The magnetic field at the origin due to the current flowing in the wire shown is 
1
-₀ I8π a(i+k)
2
₀ I2π a(i+k)
3
₀ I8π a(-i+k)
4
₀ I4π a√(2)(i-k)
05
PYQ 2011
medium
physics ID: bitsat-2
A steady current is set up in a cubic network composed of wires of equal resistance and length as shown. What is the magnetic field at the centre P due to the cubic network?
1
₀ 2I4π d
2
₀ 2I4π √(2)d
3
0
4
₀ 6π I4π d
06
PYQ 2012
medium
physics ID: bitsat-2
A horizontal overhead powerline is at a height of 4m from the ground and carries a current of 100A from east to west. The magnetic field directly below it on the ground is . What is the magnetic field at this point?
1
southward
2
northward
3
southward
4
northward
07
PYQ 2013
medium
physics ID: bitsat-2
Two parallel conductors carry current in opposite directions as shown in figure. One conductor carries a current of 10.0 A. Point C is a distance to the right of the 10.0 A current. If and is adjusted so that the magnetic field at C is zero, the value of the current is 
1
10.0 A
2
30.0 A
3
8.0 A
4
18.0 A
08
PYQ 2013
easy
physics ID: bitsat-2
Two parallel conductors carry current in opposite directions as shown in figure. One conductor carries a current of . Point is a distance to the right of the current. If and is adjusted so that the magnetic field at is zero, the value of the current is
1
10.0 A
2
30.0A
3
8.0A
4
18.0A
09
PYQ 2014
medium
physics ID: bitsat-2
A narrow beam of protons and deuterons, each having the same momentum, enters a region of uniform magnetic field directed perpendicular to their direction of momentum. The ratio of the radii of the circular paths described by them is:
1
2
3
4
10
PYQ 2015
medium
physics ID: bitsat-2
A long straight wire along the -axis carries a current in the negative -direction. The magnetic vector field at a point having coordinates in the plane is:
1
2
3
4
11
PYQ 2015
medium
physics ID: bitsat-2
Two particles and having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describe circular paths of radii and respectively. The ratio of masses of and is:
1
2
3
4
12
PYQ 2015
medium
physics ID: bitsat-2
A charged particle moving in a uniform magnetic field loses of its kinetic energy. The radius of curvature of its path changes by:
1
2
3
4
13
PYQ 2015
medium
physics ID: bitsat-2
A charged particle moving in a uniform magnetic field and losses of its kinetic energy. The radius of curvature of its path changes by
1
2%
2
4%
3
10%
4
12%
14
PYQ 2016
medium
physics ID: bitsat-2
A wire carrying current I has the shape as shown in the adjoining figure. Linear parts of the wire are very long and parallel to X–axis while the semicircular portion of radius R lies in the Y-Z plane. Magnetic field at point O is: 
1
2
3
4
vecB=(mu₀ I)/(4π R)(hati+2hatk)
15
PYQ 2016
medium
physics ID: bitsat-2
A deuteron of kinetic energy 50keV is describing a circular orbit of radius 0.5m in a plane perpendicular to the magnetic field B. The kinetic energy of the proton that describes a circular orbit of radius 0.5m in the same plane with the same B is:
1
2
3
4
200keV
16
PYQ 2017
medium
physics ID: bitsat-2
Two long, straight, parallel wires carry steady currents I and -I respectively. The distance between the wires is d. At a certain instant of time, a point charge q is at a point equidistant from the two wires. The instantaneous velocity v is perpendicular to this plane. The magnitude of the force due to the magnetic field acting on the charge is
1
2
3
4
0
17
PYQ 2017
medium
physics ID: bitsat-2
A charged particle moves perpendicular to a magnetic field. Then
1
kinetic energy changes but the momentum is constant
2
the momentum changes but the kinetic energy is constant
3
both momentum and kinetic energy of the particle are not constant
4
both momentum and kinetic energy of the particle are constant
18
PYQ 2018
medium
physics ID: bitsat-2
A charged particle enters a uniform magnetic field with a certain velocity. The power delivered to the particle by the magnetic field depends on:
1
force exerted by magnetic field and velocity
2
angular speed ω and radius of circular path
3
angular speed ω and acceleration of the particle
4
None of these
19
PYQ 2018
medium
physics ID: bitsat-2
Two long parallel wires carry equal current i flowing in the same direction and are at a distance 2d apart. The magnetic field at a point lying on the perpendicular bisector joining the wires and at a distance x from the midpoint is:
1
2
3
4
(mu₀ i d)/((d² + x²))
20
PYQ 2019
medium
physics ID: bitsat-2
A charged particle moving in a uniform magnetic field loses 4% of its kinetic energy. The radius of curvature of its path changes by
1
2
3
4
12%
21
PYQ 2019
medium
physics ID: bitsat-2
A long straight wire along the Z-axis carries a current I in the negative Z-direction. The magnetic vector field vecB at a point having coordinates (x,y) in the Z=0 plane is
1
2
3
4
(mu₀ I)/(2π(x²+y²))(-yhati+xhatj)
22
PYQ 2019
medium
physics ID: bitsat-2
Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describe circular paths of radii R₁ and R₂ respectively. The ratio of masses of X and Y is
1
2
3
4
((R₂)/(R₁))²
23
PYQ 2020
medium
physics ID: bitsat-2
A wire carrying current I has the shape as shown in the adjoining figure. Linear parts of the wire are very long and parallel to the X-axis while the semicircular portion of radius R lies in the YZ-plane. Magnetic field at point O is: 
1
2
3
4
vecB=(mu₀ I)/(4π R)(hati+2hatk)
24
PYQ 2020
medium
physics ID: bitsat-2
A deuteron of kinetic energy 50keV is describing a circular orbit of radius 0.5m in a plane perpendicular to a magnetic field B. The kinetic energy of the proton that describes a circular orbit of radius 0.5m in the same plane with the same B is:
1
2
3
4
100keV
25
PYQ 2021
medium
physics ID: bitsat-2
Two very long, straight, parallel wires carry steady currents I and -I respectively. The distance between the wires is d. At a certain instant of time, a point charge q is at a point equidistant from the two wires, in the plane of the wires. Its instantaneous velocity is perpendicular to this plane. The magnitude of the force due to the magnetic field acting on the charge at this instant is
1
(mu₀ I q v)/(2π d)
2
(mu₀ I q v)/(π d)
3
(2mu₀ I q v)/(π d)
4
(mu₀ I q v)/(π d)
26
PYQ 2021
medium
physics ID: bitsat-2
A charged particle moves through a magnetic field perpendicular to its direction. Then
1
kinetic energy changes but the momentum is constant
2
the momentum changes but the kinetic energy is constant
3
both momentum and kinetic energy of the particle are not constant
4
both momentum and kinetic energy of the particle are constant
27
PYQ 2023
medium
physics ID: bitsat-2
A charged particle is moving in a uniform magnetic field T. If it has an acceleration of m/s², then the value of will be:
1
2
3
4
28
PYQ 2023
medium
physics ID: bitsat-2
The free space inside a current carrying toroid is filled with a material of susceptibility . The percentage increase in the value of magnetic field inside the toroid will be:
1
2%
2
0.2%
3
0.1%
4
1%
29
PYQ 2023
medium
physics ID: bitsat-2
A conducting loop of radius cm is placed perpendicular to a uniform magnetic field of 0.5T. The magnetic field is decreased to zero in 0.5 s at a steady rate. The induced emf in the circular loop at 0.25s is:
1
emf = 1 mV
2
emf = 10 mV
3
emf = 100 mV
4
emf = 5 mV