I. Mass
II. Density
III. Temperature
IV. Nature of substance
which of the above affect diffusion?

The blade of a hoe feel colder to touch in the morning than the wooden handle because the

I. They should be identical
II. They should originate from the same source.
III. They should be coherent.
IV. They should be monochromatic.
from the statements above, the conditions for two waves to interfere are?

The phenomenon of light bending round an obstacle is?