An electron and a proton having mass $$m_e$$ and $$m_p$$ respectively, initially at rest, move through the same distance '$$s$$' in a uniform electric field '$$E$$'. If the time taken by them to cover that distance is $$t_e$$ and $$t_p$$ respectively, then $$t_e / t_p$$ is equal to:

The force between two electric point charges at rest in air is $$F_1$$ When the same arrangement is kept inside water, the force between them is $$F_2$$. Which of the following statement is correct?

Which of the following diagram represents the variation of the electric field with distance r from the centre of a uniformly charged non-conducting sphere of radius R?

Charge on electron is