Question

If wavelengths of maximum intensity of radiations emitted by the sun and the moon are $0.5 \times 10 ^ { - 6 } \mathrm {~m}$ and $10 ^ { - 4 } \mathrm {~m}$ respectively, the ratio of their temperatures is

• A. 1/100
• B. 1/200
• C. 100
• D. 200

Answer 1

Answer: (D)

200

Answer 2

$\frac { T _ { 1 } } { T _ { 2 } } = \frac { \lambda _ { 2 } } { \lambda _ { 1 } }$

⇒$\frac { 10 ^ { - 4 } } { 0.5 \times 10 ^ { - 5 } }$=200.