The magnetic field at the point of intersection of diagonals of a square wire loop of side carrying a current is
1
2
3
4
Official Solution
Correct Option: (4)
We can have the figure as follows
The net magnetic field at the point of intersection of the diagonal would be given by
Aliter
02
PYQ 2014
easy
physicsID: wbjee-20
A long conducting wire carrying a current is bent at (see figure). The magnetic field at a point on the right bisector of bending angle at a distance d from the bend is is the permeability of free space)
1
2
3
4
Official Solution
Correct Option: (4)
We know that
03
PYQ 2015
medium
physicsID: wbjee-20
Two particles, and , having equal charges, after being accelerated through the same potential difference enter into a region of uniform magnetic field and the particles describe circular paths of radii and , respectively. The ratio of the masses of and is
1
2
3
4
Official Solution
Correct Option: (3)
Radius of circular path followed by charged particle is given by
where, is kinetic energy of particle. Charged particle is accelerated through some potential difference , such that kinetic energy of particle is
As the two charged particles of same magnitude and being accelerated through same potential, enters into a uniform magnetic field region, then So,
04
PYQ 2016
medium
physicsID: wbjee-20
A particle of mass ????and carrying a charge ????enters with a velocity ????perpendicular to a uniform magnetic field. The time period of rotation of the particle
1
Decreases with increase of velocity v
2
Increases with increase of radius of the orbit
3
Depends only on magnetic field
4
Depends on magnetic field and (q/m) of the particle
Official Solution
Correct Option: (4)
05
PYQ 2016
medium
physicsID: wbjee-20
The magnetic field intensity at the centre of cubical cage of identical wires of length ?a? due to a current I flowing as shown in the fiigure is
1
2
3
0
4
I/2a
Official Solution
Correct Option: (3)
For symmetrical current distribution, magnetic field at the centre due to all current carrying conductors will get cancelled. Hence
06
PYQ 2017
medium
physicsID: wbjee-20
The magnetic field due to a current in a straight wire segment of length at a point on its perpendicular bisector at a distance
1
decreases as
2
decreases as
3
decreases as
4
approaches a finite limit as
Official Solution
Correct Option: (2)
By Biot-Savart's law, the magnetic field due to a current carrying wire is
So, So, the magnetic field due to current decreases as inverse square of distance of the point of observation.
07
PYQ 2023
hard
physicsID: wbjee-20
A charged particle in a uniform magnetic field starts moving from the origin with velocity m/s.The trajectory of the particle and the time at which it reaches 2m above the x-y plane are
1
Helical path, sec.
2
Circular path, sec.
3
Circular path, sec.
4
Helical path, sec.
Official Solution
Correct Option: (1)
Given: Magnetic field: Initial velocity: m/s
Explanation: The velocity has two components: - Perpendicular to : → causes circular motion in the x-y plane - Parallel to : → causes linear motion along the z-axis
Therefore, the trajectory is a helical path.
To find the time when the particle is 2 m above the x-y plane: Vertical velocity: m/s Displacement in z-direction: m Using : sec
Final Answer: Helical path, sec Correct option: (B)
