A system `S` receives heat continuously from an electric heater of power `10 W`. The temperature of `S` becomes constant at `50^(@)C` when the surrounding temperature is `20^(@)C`. After the heater is switched off, `S` cools from `35.1^(@)C` to `34.9^(@)C` in `1 minute`. the heat capacity of `S` is

Options

A. `750J(.^(@)C)^(-1)`
B. `1500J(.^(@)C)^(-1)`
C. `3000J(.^(@)C)^(-1)`
D. `6000J(.^(@)C)^(-1)`

Answer

B

Explanation

`(dQ)/(dt) prop T -T_(0) , 10 = beta (50 -20), beta = (1)/(3)`
`(ms)((theta_(1)-theta_(2)))/(t) =beta((theta_(1)+theta_(2))/(2)-theta_(s))`
here `theta_(1) = 35. 1^(@) C, theta_(2) = 34.9^(@)C` .