Two spheres P and Q, of same colour having radii 8 cm and 2 cm are maintained at temperatures 1270 C and 5270 C respectively. The ratio of energy radiated by P and Q is
1
Total energy radiated from a body Q=Aϵσ T4 t⇒ Q αAT4 αr2 T4 (∵ A=4πr2)⇒QpQQ= (rprQ)2 (TpTQ)4=(82)2{(273+127)(273+527)}4=1