question_answer

A student measures magnitude of electric field due to a charged sphere S by two different ways. I. He places a very small similarly charged sphere near S and then measures force per unit charge. II. He places a large similarly charged sphere near S and then measures force per unit charge. Let his recordings are \[{{E}_{1}}\]and \[{{E}_{2}}.\]

A) \[{{E}_{2}}>{{E}_{1}},\]when charge on S is negative

B) \[{{E}_{1}}={{E}_{2}}\]

C) \[{{E}_{1}}>{{E}_{2}}\]

D) \[{{E}_{2}}>{{E}_{1}},\]when charge on S is positive

Correct Answer: C

Solution :

I. II.  In II case, mean distance between charges is more due to mutual repulsion. \[\therefore \]\[{{E}_{2}}<{{E}_{1}}\]