
Assertion: When two positive point charges move away from each other, their electrostatic potential energy decreases.
Reason: Change in potential energy between two points is equal to the work done by electrostatic forces.


Important Questions on Electrostatics
Assertion: When two charged spheres are connected to each other by a thin conducting wire, charge flow from bigger sphere to smaller sphere if initial charges on them are same.
Reason: Electrostatic potential energy will be lost in redistribution of charges.

Assertion: Half of the ring is uniformly positively charged and other half uniformly negatively charged. Then, electric field and electric potential both are zero at centre.
Reason: At the centre of uniformly charged ring, electric field is zero.

Assertion: Spherical shell in the shown figure has a charge and shell has charge When these two are connected by a thin conducting wire, the whole of the electrostatic potential difference between the shell is lost.
Reason: Whole of the inner charge will transfer to outer shell .

Assertion: A charged sphere has a radius . If at a distance from the surface towards centre, the potential is and a distance from the surface towards infinity, the potential is then .
Reason: Inside a solid sphere, variation is parabolic. Where is the distance from centre?

Assertion: For a non-uniformly charged thin circular ring with net charge zero, the electric field at any point on axis of the ring is zero.
Reason: For a non-uniformly charged thin circular ring with net charge zero, the electric potential at each point on axis of the ring is zero.

Assertion: In a region where a uniform electric field exists, the net charge within a volume of any size is zero.
Reason: The electric flux within any closed surface in the region of a uniform electric field is zero.

Assertion: We have a solid charged sphere. There are two points and is a point lying between centre and surface of the sphere. is at finite and non-zero distance from the surface outside the sphere. There will be no situation where electric potential is equal at and .
Reason: Rate of change of electric field with distance from centre merely represents, magnitude of electric potential at that point.

Assertion: Cyclotron is used to accelerate heavy charged particles, such as a proton. It is not suitable for accelerating light charged particles such as electrons.
Reason: Specific charge of a proton is more than compared to the electron.
