Assertion and Reason Questions Chapter-1
Electric
Charges and Fields
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): Electric field inside a conductor is always zero.
Reason (R): Charges in a conductor move to the surface until the
electric field inside is zero.
2. Assertion (A): Electric field lines never intersect each other.
Reason (R): At any point, there can be only one direction of the
electric field.
3. Assertion (A): The electric potential inside a charged spherical conductor is
constant.
Reason (R): The electric field inside a charged spherical
conductor is zero.
4. Assertion (A): Electric field at a point on the axis of a dipole is directed
along the dipole axis.
Reason (R): The electric field due to a dipole is stronger near
the axis than at the equatorial position.
5. Assertion (A): Electric field lines start from positive charges and end on
negative charges.
Reason (R): Electric field lines represent the direction of force
experienced by a positive test charge.
6. Assertion (A): A dipole placed in a uniform electric field experiences both
torque and net force.
Reason (R): The torque on the dipole causes it to rotate and align
with the electric field direction.
7. Assertion (A): The electric field due to a point charge decreases with
distance as 1/r².
Reason (R): The electric potential due to a point charge decreases
with distance as 1/r.
8. Assertion (A): The electric field at any point on the surface of a charged
spherical conductor is the same.
Reason (R): A charged spherical conductor behaves like a point
charge placed at its center.
9. Assertion (A): Coulomb’s force between two charges is independent of the
medium between them.
Reason (R): Coulomb's force depends only on the magnitude of
charges and the distance between them.
10. Assertion (A): The electrostatic force between two charges is inversely
proportional to the product of their magnitudes.
Reason (R): The electrostatic force between two charges depends on
the distance between the charges.
11. Assertion (A): The electrostatic force on a charge due to another charge can
be attractive or repulsive.
Reason (R): The electrostatic force follows the inverse square
law.
12. Assertion (A): The net force on a test charge placed inside a charged
spherical shell is zero.
Reason (R): The electric field inside a charged spherical shell is
zero.
13. Assertion (A): A charged conductor always has its charge distributed
uniformly over its surface.
Reason (R): Charges on a conductor move to minimize potential
energy.
14. Assertion (A): The electric potential due to a dipole at an axial point is
zero.
Reason (R): The electric potential at the midpoint of a dipole is
zero.
15. Assertion (A): A point charge placed outside a uniformly charged spherical
shell experiences an electric force as if all the charge were concentrated at
the center of the shell.
Reason (R): A charged spherical shell behaves like a point charge
for points outside the shell.
16. Assertion (A): The work done in moving a test charge between two points on
an equipotential surface is zero.
Reason (R): The potential difference between any two points on an
equipotential surface is zero.
17. Assertion (A): The electric flux through a closed surface depends only on
the charge enclosed within the surface.
Reason (R): The electric flux through a closed surface is
independent of the shape of the surface.
18. Assertion (A): The electric potential due to a dipole at the equatorial line
is zero.
Reason (R): The potential due to a dipole at any point on the
equatorial line is equal in magnitude but opposite in sign for the positive and
negative charges.
19. Assertion (A): A charged conductor in equilibrium has no net motion of
charge.
Reason (R): The electric field inside a conductor is zero in
electrostatic equilibrium.
20. Assertion (A): The electric field due to a uniformly charged infinite plane
sheet is constant at any point near it.
Reason (R): The electric field due to an infinite plane sheet is
independent of distance from the sheet.
21. Assertion (A): The electric field at any point due to an electric dipole is
inversely proportional to the cube of the distance from the dipole.
Reason (R): The electric field due to a dipole at large distances
falls off faster than that due to a point charge.
22. Assertion (A): The force between two charges placed in a medium decreases
with an increase in the dielectric constant of the medium.
Reason (R): The dielectric constant reduces the effective force
between charges by weakening the electric field.
23. Assertion (A): The potential energy of a system of two like charges is
positive.
Reason (R): Like charges repel each other, increasing the energy
of the system.
24. Assertion (A): The electric flux through a Gaussian surface enclosing an
electric dipole is zero.
Reason (R): The net charge enclosed by the Gaussian surface is
zero.
25. Assertion (A): A positive test charge placed in an electric field
experiences a force in the direction of the field.
Reason (R): The electric field is defined as the force experienced
by a unit positive charge.
26. Assertion (A): The electric field inside a uniformly charged solid sphere is
non-zero.
Reason (R): The charges inside the sphere contribute to the
electric field within the sphere.
27. Assertion (A): The magnitude of electrostatic force between two point
charges is inversely proportional to the square of the distance between them.
Reason (R): Coulomb’s law governs the interaction between point
charges.
28. Assertion (A): The electric potential energy of two opposite charges is
negative.
Reason (R): Opposite charges attract each other, reducing the
energy of the system.
29. Assertion (A): The electric field at the surface of a conductor is
perpendicular to the surface.
Reason (R): Charges on a conductor move until the electric field
inside is zero.
30. Assertion (A): Electric field lines are continuous curves without breaks.
Reason (R): Electric field lines represent the direction of the
force acting on a positive test charge.
31. Assertion (A): The electric field due to a uniformly charged ring is zero at
the center of the ring.
Reason (R): The net force at the center of the ring due to all the
charges is zero.
32. Assertion (A): Two charges of the same magnitude but opposite signs placed
at a distance form a dipole.
Reason (R): A dipole is characterized by two equal and opposite
charges separated by a small distance.
33. Assertion (A): Electric field lines can intersect.
Reason (R): Two electric field lines can cross each other if the
magnitudes of the electric field at the point of intersection are the same.
34. Assertion (A): The electric field inside a uniformly charged spherical shell
is zero.
Reason (R): The net charge enclosed by a Gaussian surface inside
the shell is zero.
35. Assertion (A): The force between two charges in a medium is smaller than the
force between them in a vacuum.
Reason (R): The electric permittivity of a medium is greater than
that of a vacuum.
36. Assertion (A): The electric potential due to a point charge decreases as we
move away from the charge.
Reason (R): The electric field due to a point charge decreases
inversely with the square of the distance.
37. Assertion (A): The electrostatic potential energy of a system of two charges
of opposite sign is negative.
Reason (R): Opposite charges attract each other, resulting in
negative potential energy.
38. Assertion (A): Electric field lines can never form closed loops.
Reason (R): The electric field is a conservative field.
39. Assertion (A): The electric potential at a point midway between two equal
like charges is zero.
Reason (R): The electric field at a point midway between two equal
like charges is zero.
40. Assertion (A): The electric field at a point due to a point charge is
directed along the radial line.
Reason (R): The electric field is the force per unit charge
experienced by a positive test charge.
41. Assertion (A): Two similar charges placed close to each other will
experience a repulsive force.
Reason (R): Like charges repel each other according to Coulomb’s
law.
42. Assertion (A): A conductor in electrostatic equilibrium has no net electric
field inside it.
Reason (R): Charges in a conductor move to the surface, creating
an electric field that cancels out any internal field.
43. Assertion (A): The electric field at the center of a uniformly charged ring
is zero.
Reason (R): The contributions of electric field vectors from
different parts of the ring cancel out at the center.
44. Assertion (A): The electric potential is constant throughout the interior of
a conductor in electrostatic equilibrium.
Reason (R): The electric field inside a conductor is zero in
electrostatic equilibrium.
45. Assertion (A): The potential at any point outside a uniformly charged
spherical shell is the same as that of a point charge placed at the center of
the shell.
Reason (R): The electric field due to a uniformly charged shell
behaves as if all the charge is concentrated at the center of the shell for
points outside the shell.
46. Assertion (A): The electrostatic force between two charges is conservative
in nature.
Reason (R): Work done in moving a charge between two points
depends only on the initial and final positions, not on the path taken.
47. Assertion (A): The electric field inside a hollow spherical conductor is
zero.
Reason (R): There is no charge enclosed within the hollow region
of the conductor.
48. Assertion (A): The electric field at the surface of a conductor is always
perpendicular to the surface.
Reason (R): If the electric field had a component parallel to the
surface, the charges would move, violating electrostatic equilibrium.
49. Assertion (A): The electric potential at a point on the axis of an electric
dipole is zero if the point is equidistant from both charges.
Reason (R): The electric potential due to the positive charge
cancels out the potential due to the negative charge at the midpoint.
50. Assertion (A): Electric flux through a closed surface depends only on the
net charge enclosed by the surface.
Reason (R): According to Gauss’s law, electric flux through a
closed surface is proportional to the net charge enclosed.