JEE Class main Answered

figure shows the thin insulating charged rod having linear charge density λ is at equilibrium

due to electrostatic force F and its own weight ( mg ) , where m is mass of rod and g is acceleration due to gravity

Let us divide the rod into small segments of length dl . Each segment has charge dq = λ dl

Electrostatice force F on rod due to uniform electric field E is

Hence at equilibrium

F =  ( m g )

( E λ l ) = ( m g )

E = ( m g ) / ( λ l ) = ( 2 × 10 ) / ( 10 × 1 ) = 2 N/C