Read the following statements : A . When small temperature difference between a liquid and its surrounding…

Read the following statements :
A. When small temperature difference between a liquid and its surrounding is doubled the rate of loss of heat of the liquid becomes twice.

B. Two bodies P and Q having equal surface areas are maintained at temperature 10°C and 20°C. The thermal radiation emitted in a given time by P and Q are in the ratio 1:1.15

C. A carnot Engine working between 100 K and 400 K has an efficiency of 75%

D. When small temperature difference between a liquid and its surrounding is quadrupled, the rate of loss of heat of the liquid becomes twice.

Choose the correct answer from the options given below :

  1. A,B,C only
  2. A,B only
  3. A,C only
  4. B,C,D only

Solution

A. by Newton's law of cooling -dθdtΔθ

B. According to Stephan's law dHdt=σeAT4HPHQ=TPTQ4=2832934

HP:HQ=11.034=1:1.034=1:1.15

B is correct

C. The efficiency of the Carnot cycle is given byη=1-T1T2=1-100400=34=75%

D. is wrong as according to the Newton's law of cooling dθdtΔT

Asked in: JEE Main 2022 (27 Jul Shift 1)

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