Assertion:- Electric field lines are always perpendicular to the surface of conductor.

Reason:- Electric field is always perpendicular to equipotential surface.

Assertion:- Electrostatic field lines are perpendicular to the surface of conductor.

Reason:- Surfaces of a conductor are equipotential.

Assertion: An electrostatic field represent as

$\overrightarrow{E}=E_x\hat{i}+E_y\hat{j}+E_z\hat{k}$ satisfies $\overrightarrow{\nabla }\times \overrightarrow{E}=0$

Reason: $E_x, E_y, E_z$ are independent of each other.

Assertion: Electric field inside conductor is zero in electrostatics. 

Reason: Charge appears on surface of conductor.

Assertion: Heart can be considered as dipole.

Reason: Electric flux and electric field are same as dipole.

Assertion: Electric flux density is independent of medium.

Reason: It depends only on distance and charge.

Assertion: For a charged shell, potential inside shell depends only on the field inside shell.

Reason: Potential of shell may be determined only by the field outside.

Assertion :- Electrostatic energy does not follow superposition principle. 

Reason :- Electrostatic energy density is a quadratic function.

Assertion: We cannot find electric field from Gauss's law for unsymmetrical charge distribution.

Reason: Gauss's law is not applicable for unsymmetrical charge distribution.