Question

A 100 W electric bulb was switched on in a 2.5 m $\times$ 3m \times 3 size thermally insulated room having a temperature of 20⁰C. The room temperature at the end of 24 hours will be                                                                       

      (a) 321⁰C                                                            (b) 341⁰C

      (c) 450⁰C                                                            (d) 470⁰C