NTA Abhyas JEE Main2020PhysicsThermal Properties of MatterPractice
The temperature of a liquid drops from 365 K to 361 K in 2 minutes . The time during which temperature of the liquid drops from 344 K to 342 K is (Room temperature is 293 K ) -
Options
- A84 s
- B72 s
- C66 s
- D60 s
Correct answer
A. 84 s
Step-by-step solution
From Newton's law of cooling, 365 - 361 2 = K 365 + 361 2 - 293 ..... (1) 344 - 342 t = K 344 + 342 2 - 293 .... (2) Equation 1 ÷ ( 2 ) t = 365 + 361 - 586 344 + 342 - 586 = 140 100 m i n = 140 × 60 100 s = 84 s