Athin ring of radius r is uniformly charged with the total positive charge q. 1. find the electric field at distance h right above the center of the ring

Explanation:

If charge Q is uniformly distributed over the ring then for small element of the ring the charge will be given as

now electric field due to this small element on the axis of ring at height "h" is given as

now since this electric field is radially in the direction of joining the position of charge to the given point

so net field due to ring will be along the axis of ring

so we have

d. platinum would have the greatest temperature increase because it has the lowest specific heat.

i think it would be 5