Sources of Energy — Science STD 10 — Question

Write the common food chain of a pond ecosystem.

What happens when methane reacts with chlorine? Give equation of the reaction which takes place.

What type of reaction is represented by the digestion of food in our body?

A ray of light going towards the focus of a convex mirror becomes parallel to the principal axis after reflection from the mirror. Draw a labelled diagram to represent this situation

Is 'nutrition' a necessity for an organism? Discuss.

State the physical conditions of reactants in which the reaction will not take place.

By how much time the day would have been shorter if the earth had no atmosphere?

Out of an A.C. generator and a D.C. generator:

1. Which one uses a commutator (split rings)?
2. Which one uses slip rings?

What are those organisms called which bear both the sex organs in the same individiual. Cive one example of such organism.