Temperature of 100 g of water in a thermoflask remains fixed for a pretty long time at `50^(@)C`. An equal mass of sand at `20^(@)C` is poured in the flask and shaken for some time so that the temperature of the mixture is `40^(@)`. Now the experiment is repeated with 100g of a liquid at `50^(@) C` and an equal amount of sand at `20^(@)C` when the temperature of the mixture is found to be `30^(@)C` The specific heat of the liquid `(in KJ//KgxK)` is

Options

A. `1.05`
B. `2.10`
C. `4.20`
D. `1.951`

Answer

B

Explanation

`100 xx S_(w)xx10 =100xxS_(S)xx20`
`100 xx S_(l) xx 20 = 100 xx S_(S) xx10`
`S_(w),S_(l),S_(S)` are specific heat capacities of water liquid & sand respectively.
`S_(l)=(S_(W))/(2)=2.10kJ..KgxxK`.