Assertion and Reason Questions Chapter-4 Moving Charges and Magnetism
Assertion (A) and other labelled Reason (R). Select the correct answer to these
questions from the options as given below.
A. Both A and R are true, and R is the correct explanation of A.
B. Both A and R are true, but R is not the correct explanation of A.
C. A is true, but R is false.
D. A is false, but R is true.
1. Assertion (A): A charged particle moving in a magnetic field experiences a
force perpendicular to its velocity.
Reason (R): This force is described by the Lorentz force law.
2. Assertion (A): The magnetic field inside a long straight current-carrying
solenoid is uniform.
Reason (R): The field lines inside the solenoid are parallel and
equally spaced.
3. Assertion (A): The direction of the magnetic field due to a current-carrying
wire can be determined using the right-hand thumb rule.
Reason (R): This rule states that if the thumb points in the
direction of the current, the curled fingers indicate the magnetic field
direction.
4. Assertion (A): A magnetic field can exert a force on a stationary charged
particle.
Reason (R): The force on a charged particle is independent of its
velocity.
5. Assertion (A): The force experienced by a current-carrying conductor in a
magnetic field depends on the angle between the current and the magnetic field.
Reason (R): Maximum force occurs when the angle is 90 degrees.
6. Assertion (A): The magnetic field lines of a bar magnet form closed loops.
Reason (R): Magnetic field lines do not have a beginning or an
end.
7. Assertion (A): A charged particle moving in a uniform magnetic field will
follow a circular path.
Reason (R): The magnetic force acts as the centripetal force on
the particle.
8. Assertion (A): The magnetic field inside a current-carrying loop is stronger
at the center than at the edges.
Reason (R): The magnetic field strength decreases with distance
from the loop.
9. Assertion (A): Electromagnetic induction can occur without the relative
motion of the magnet and coil.
Reason (R): Changing the magnetic field strength over time induces
an emf.
10. Assertion (A): The Hall effect can be used to determine the type of charge
carriers in a conductor.
Reason (R): The sign of the Hall voltage indicates whether the
charge carriers are positive or negative.
11. Assertion (A): A solenoid can act as a magnet when an electric current flows
through it.
Reason (R): The magnetic field generated inside the solenoid is
similar to that of a bar magnet.
12. Assertion (A): The force on a charged particle in a magnetic field is zero
when the particle moves parallel to the field lines.
Reason (R): The magnetic force depends on the sine of the angle
between the velocity and magnetic field vectors.
13. Assertion (A): The magnetic field produced by a current-carrying conductor
can be measured using a compass.
Reason (R): The compass needle aligns itself with the magnetic
field direction.
14. Assertion (A): An electron moving in a magnetic field experiences a force
that can change its speed.
Reason (R): The magnetic force acts perpendicular to the velocity
of the electron.
15. Assertion (A): The right-hand rule can be used to determine the direction of
the magnetic field around a current-carrying conductor.
Reason (R): The direction of the field is perpendicular to the
current flow.
16. Assertion (A): A magnetic field can do work on a charged particle.
Reason (R): The magnetic force can change the kinetic energy of
the particle.
17. Assertion (A): The force on a current-carrying conductor in a magnetic field
can be increased by increasing the current.
Reason (R): The force is directly proportional to the current
flowing through the conductor.
18. Assertion (A): The direction of the magnetic field around a straight
conductor can be reversed by reversing the current direction.
Reason (R): The right-hand rule shows the direction of the field
is dependent on current flow.
19. Assertion (A): A charged particle moving in a circular path in a magnetic
field experiences a constant speed.
Reason (R): The magnetic force acts as a centripetal force.
20. Assertion (A): The magnetic field inside a solenoid is uniform, while that
outside is weak.
Reason (R): The field lines inside the solenoid are dense and
parallel.
21. Assertion (A): When the angle between the magnetic field and the velocity of
a charged particle is 90 degrees, the magnetic force is at its minimum.
Reason (R): The force is given by the equation F=qvBsin(θ).
22. Assertion (A): The force on a current-carrying wire in a magnetic field is
affected by the length of the wire.
Reason (R): Longer wires experience greater magnetic forces.
23. Assertion (A): Electrons in a wire moving through a magnetic field
experience a magnetic force.
Reason (R): The motion of the electrons creates an electric field
in the wire.
24. Assertion (A): The magnetic field due to a circular loop of wire is
concentrated at the center of the loop.
Reason (R): The field strength decreases as one moves away from
the loop.
25. Assertion (A): The Hall voltage is directly proportional to the magnetic
field strength.
Reason (R): Increasing the magnetic field strength increases the
force on charge carriers.
26. Assertion (A): The magnetic field lines produced by two current-carrying
wires can interact with each other.
Reason (R): Like currents repel, while opposite currents attract.
27. Assertion (A): The force between two parallel current-carrying conductors
depends on the distance between them.
Reason (R): The force is inversely proportional to the distance
between the wires.
28. Assertion (A): A charged particle moving in a magnetic field will undergo
uniform circular motion.
Reason (R): The magnetic force provides a constant centripetal
force on the particle.
29. Assertion (A): The unit of magnetic field strength is Tesla.
Reason (R): 1 Tesla is defined as 1 Weber per square meter.
30. Assertion (A): The direction of the induced current in a coil can be
predicted using Lenz's law.
Reason (R): Lenz's law states that induced current will oppose the
change in magnetic flux.
31. Assertion (A): A magnetic field can exert a torque on a current loop.
Reason (R): The torque depends on the current flowing in the loop
and the area of the loop.
32. Assertion (A): The magnetic field produced by a solenoid is similar to that
of a bar magnet.
Reason (R): A solenoid has distinct north and south poles.
33. Assertion (A): The angle of deflection of a charged particle in a magnetic
field is constant.
Reason (R): The magnetic force acts perpendicular to the velocity
of the particle.
34. Assertion (A): The magnetic field strength decreases as one moves away from
a long straight current-carrying wire.
Reason (R): The magnetic field lines spread out as they move away
from the wire.
35. Assertion (A): The direction of the induced emf in a coil can change based
on the movement of the magnetic field.
Reason (R): The induced emf depends on the rate of change of
magnetic flux.
36. Assertion (A): The motion of a charged particle in a magnetic field can be
described as helical.
Reason (R): The magnetic force causes circular motion while the
electric field causes linear motion.
37. Assertion (A): A conductor carrying a current in a magnetic field will
experience a force that is independent of its orientation.
Reason (R): The force is given by the equation F=BILsin(θ).
38. Assertion (A): The force between two current-carrying conductors can be
attractive or repulsive.
Reason (R): The nature of the force depends on the direction of
the currents in the wires.
39. Assertion (A): The magnetic field inside a solenoid can be increased by
increasing the current through it.
Reason (R): The strength of the magnetic field is directly
proportional to the current flowing through the solenoid.
40. Assertion (A): A magnetic field can induce an emf in a closed loop.
Reason (R): This phenomenon is explained by Faraday's law of
electromagnetic induction.
41. Assertion (A): The magnetic field due to a straight current-carrying wire is
circular.
Reason (R): The field lines form concentric circles around the
wire.
42. Assertion (A): The motion of a charged particle in a uniform magnetic field
can be described by circular motion.
Reason (R): The magnetic force acts perpendicular to the velocity
of the particle, providing centripetal force.
43. Assertion (A): The magnetic field strength is strongest at the poles of a
magnet.
Reason (R): The magnetic field lines are dense at the poles.
44. Assertion (A): The magnetic field created by a solenoid can be reversed by
reversing the current direction.
Reason (R): Changing the current direction also reverses the
polarity of the solenoid.
45. Assertion (A): The path of a charged particle in a magnetic field can be a
straight line if the velocity is parallel to the field.
Reason (R): The magnetic force is zero when the angle is zero
degrees.
46. Assertion (A): A magnetic field can do work on a charged particle.
Reason (R): The magnetic force can change the speed of the
particle.
47. Assertion (A): The force experienced by a charged particle in a magnetic
field is directly proportional to the charge of the particle.
Reason (R): The force equation includes the charge term qqq.
48. Assertion (A): A magnetic field can exist in a vacuum.
Reason (R): The magnetic field does not require a medium for
propagation.
49. Assertion (A): The torque experienced by a current-carrying loop in a
magnetic field is zero when the plane of the loop is parallel to the magnetic
field lines.
Reason (R): Torque is maximum when the plane of the loop is
perpendicular to the magnetic field.
50. Assertion (A): The magnetic field strength around a straight wire decreases
with distance.
Reason (R): The field strength is inversely proportional to the
distance from the wire.