Question

If charge density of an infinite charged plate is doubled and the distance of point charge is tripled from the infinite charged plate, then electric field is increased ____times.

Answer 1

Electric field due to an infinite charged plate is $\frac{\sigma }{2{\epsilon }_0}$ i.e, it depends only on the charge density $\left(\sigma \right)$ and independent of distance of charge from the charged plate. So, when charge density is doubled, the electric field is increased 2 times.