T wo substances A and B of equal mass m are heated at uniform rate of `6 cal s^(-1)` under similar conditions. A graph between temperature and time is shown in figure. Ratio of heat absorbed `(H_(A))/(H_(B))` by them for complete fusion is

Options

A. `(9)/(4)`
B. `(4)/(9)`
C. `(8)/(5)`
D. `(5)/(8)`

Answer

C

Explanation

`H_(A) = (6 "cal"//s) xx (6-2)s`
`H_(B) = (6"cal"//s) xx (6.5 - 4)s`
`therefore (H_(A))/(H_(B)) = (4)/(2.5) = (8)/(5)`