Define radiation. Give any two examples where heat is transferred by radiation. What is the name of invisible heat rays which transfer heat by radiation ?
(a) What is spectrum ? What is the name of glass shape used to produce a spectrum ? (b) How many colours are there in a full spectrum of white light ? Write the various colours of spectrum in the order, starting with red.
How did the invisible man first become visible?
Which of the following gives neither emission spectrum nor absorption spectrum?
