In summer we use air conditioners and in winter we use heaters. Here homeostasis is accomplished by artificial means. Explain four ways by which other living organisms cope with the situation.

We know that heat is emitted along with light when a bulb glows. .LED lamps are better than filament bulbs for maximum reduction in the consumption of electrical energy. Explain. Are there situations where filament. bulbs are used for producing Light energy? Give examples.

Light obliquely travel from glass to air , critical angle of glass is 42^@ . What is mean by critical Angle ? In which phenomenon we observe the incident angle is 40^@ ? Explain the phenomenon ?