question_answer

A positive point charge is placed at P in front of an earthed metal sheet S. Q and R are two points between P and S as shown in figure. If the electric field strength at Q and R are respectively \[{{E}_{Q}}\] and \[{{E}_{R}}\] and potential at Q and R are respectively \[{{V}_{Q}}\]and \[{{V}_{R}},\] then -

A) \[{{E}_{Q}}>{{E}_{R}}\]

B) \[{{E}_{Q}}<{{E}_{R}}\]

C) \[{{V}_{Q}}={{V}_{R}}\]

D) \[{{V}_{Q}}<{{V}_{R}}\]

Correct Answer: B

Solution :

As we are moving away from P towards sheet S spacing between electric lines of force is increasing.

\[\therefore \,\,\,{{E}_{R}}<{{E}_{Q}}\]

In the direction of electric field potential decreases.

\[\therefore \,\,\,{{V}_{R}}<{{V}_{Q}}\]