question_answer

Directions: In the following questions, a statement of Assertion (A) is followed by a statement of Reason:

(R). Mark the correct choice as:

Assertion (A): Three equal charges are situated on a circle of radius r such that they form an equilateral triangle, then the electric field intensity at the centre is zero.

Reason (R): The force on unit positive charge at the centre, due to the three equal charges are represented by the three sides of a triangle taken in the same order.

Therefore, electric field intensity at centre is zero.

A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)

B) Both Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A)

C) Assertion (A) is true but Reason (R) is false            

D) Assertion (A) is false and Reason (R) is also false

Correct Answer: A

Solution :

(a) Resultant of electric intensity at O due to Band C is equal and opposite to that due to A.