MHT CET202122 Sep 2021Evening ShiftPhysicsThermal Properties of MatterActual
The emissive power of sphere of area 0.04 ~m ^2 is 0.7 kcal s ⁻¹ ~m ⁻² . The amount of heat radiated in 20 second is
Options
- A2.8 kcal s ⁻¹ ~m ⁻²
- B0.28 kcal s ⁻¹ ~m ⁻²
- C5.6 kcal s ⁻¹ ~m ⁻²
- D0.56 kcal s ⁻¹ ~m ⁻²
Correct answer
D. 0.56 kcal s ⁻¹ ~m ⁻²
Step-by-step solution
Emissive power E= Q A t Q=E A t=0.7 0.04 20=0.56 kcal s ⁻¹ ~m ⁻²