Question

Two blocks are at ${20}^{o}C$ and ${80}^{o}C$, respectively. The specific heat of the block at higher temperature is more than that of the block at the lower temperature. Which of the following is true about the final temperature $T_f$ when the two blocks are brought into contact (assuming that no heat is lost to the surroundings)?

• A. $T_f$ will be ${50}^{o}C$
• B. $T_f$ will be more than ${50}^{o}C$
• C. $T_f$ will be less than ${50}^{o}C$
• D. $T_f$ can be either more than or less than ${50}^{o}C$ depending on the precise variation of the specific heat with temperature.

Answer 1

The correct option is B $T_f$ will be more than ${50}^{o}C$

Final temperature will be more than ${50}^{o}C$ because the specific heat of the block at hogher temperature is less than that of at lower temperature. And hence it will release less heat and less heat is being absorbed.