Question

what will be the work done if a Unit chargeis moved from infinity to a distance 'R' from infinitely large charged sheet? CUT TO POINT ANSWER PLEASE

Answer 1

We know, W = k. q₁q₂/ [1/r₁² - r₂² ]

Here, r₁ = R
r₂ = ∞

Substitute their values, 
 W = k. q₁q₂/ [1/R - 1/∞]
 W = k. q₁q₂/ [1/R]
 W = k. q₁q₂/ R

Hope this helps!