A hollow spherical cavity behaves like a blackbody

PHYSICS · Single correct · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics

Problem

A hollow spherical cavity behaves like a blackbody. At

900\,\text{K}

its surface area is

A

and it radiates

150\,\text{W}

. The area is then increased to

1.10A

while keeping the radiated power the same at

150\,\text{W}

. What is the new temperature of the cavity? (a)

920\,\text{K}

(b)

820\,\text{K}

(c)

879\,\text{K}

(d)

860\,\text{K}