Answer:
Brightness of sun surface = 2.2045 times of brightness of sunspot
Explanation:
We have given temperature of sunspot [tex]T_1=4760K[/tex]
Temperature of solar surface [tex]T_2=5800K[/tex]
Now according to Stefan's law
[tex]\frac{L}{A}=\sigma T^4[/tex], here L is radiated power, A is area, [tex]\sigma[/tex] is stefan constant
As the brightness depends on the radiated power
So [tex]\frac{brightness\ of\ sunspot}{brightness\ of\ sun\ surface}=\frac{T_1^4}{T_2^4}[/tex]
[tex]\frac{brightness\ of\ sunspot}{brightness\ of\ sun\ surface}=\frac{4760^4}{5800^4}=0.4536[/tex]
Brightness of sun surface = 2.2045 times of brightness of sunspot
