MHT CET Physics question

The emissive power of sphere of area 0.04 m is 0.7 k cal s m. The amount of heat radiated in 20 second is [MHT-CET 2021]

• (A)2.8 k cal s m
• (B)0.28 k cal s m
• (C)5.6 k cal s m
• (D)0.56 k cal s mCorrect