1. Why do the electrostatic field lines not form closed loops?
Answer:
Electric field lines do not form closed loops because the direction of an electric field is from positive to negative charge. So one can regard a line of force starting from a positive charge and ending on a negative charge. This indicates that electric field . lines do not form closed loops.
2. Why do the electric field lines never cross each other?
Answer:
The electric lines of force give the direction of the electric field. In case, two lines of force intersect, there will be two directions of the electric field at the point of intersection, which is not possible.
3. What is the electric flux through a cube of side 1 cm which encloses an electric dipole?
Answer:
Zero because the net charge of an electric dipole (+ q and – q) is zero.
4. Why are electric field lines perpendicular at a point on an equipotential surface of a conductor?
Answer:
If the electric field lines were not normal to the equipotential surface, it would have a non-zero component along the surface. To move a unit test charge against the direction of the component of the field, work would have to be done which means this surface cannot be equipotential surface.
Hence, electric field lines are perpendicular at a point on an equipotential surface of a conductor.
5. How does the electric flux due to a point charge enclosed by a spherical Gaussian surface get affected when its radius is increased?
Answer:
The electric flux due to a point charge enclosed by a spherical gaussian surface remains ‘unaffected’ when its radius is increased.
6 .Does the charge given to a metallic sphere depend on whether it is hollow or solid? Give reason for your answer.
Answer:
No, it does not, because the charge resides only on the surface of the conductor.
