Question

Twelve charges are positioned on the dial of a wall clock such that a charge Q is at the
position 1, 2Q at position 2, 3Q at 3 and so on, ending with 12Q at the position 12. If O is
at the centre of the dial, what is the force exerted on a unit charge located at O,
assuming the radius of the dial to be of unit length?

Answer 1

Here attractive force will workSo if we assume a test charge placed at centre then for numbers of right side means in opposite of -12q we have -6q so half of the force will be cancelled and the net due to both will be in direction of -12q charge.Similarly this will be followed by other number too.So the the resultant of all net forces will be somewhere b/w no. 9 and 10.So at 9:30 the hour hand will direct towards the direction of net Electric field

Answer 2

Explanation:

answer is option c

ihope it help u