Transmission Of Heat Question 157

Question: When red glass is heated in dark room it will seem

[RPET 2000]

Options:

A) Green

B) Purple

C) Black

D) Yellow

Show Answer

Answer:

Correct Answer: A

Solution:

Red and green colours are complementary to each other. When red glass is heated it absorbs green light strongly, hence according to Kirchoff’s law, the emissive power of red glass should be maximum for green light. That’s why when this heated red glass is taken in dark room it strongly emits green light and looks greenish.