The correct option is D For larger ball is four times that of the other ball
As we know
By Stefan - Boltzmann's law
ΔQ=ϵσA(T4−T40)
Given, ball is of same material and both are in same temperature.
Hence, σ,ϵ & T will be same for both balls.
Thus,
ΔQ∝A
ΔQ∝r2
where r1 is the radius of small ball.
r2 is the radius of larger ball.
Given: {d1d2=12=r1r2}
So, ΔQ1ΔQ2=(r1r2)2=(r12r1)2=14
Hence, initial rate of loss of heat for larger ball will be four times that of the smaller ball.