Electricity — Science STD 10 — Question

Why do the walls of trachea not collapse when there is less air in it?

What percentage of energy available at the producer level is transferred at successive trophic levels in a food chain?

Name the famous book written by Charles Robert Darwin.

Write the chemical equation of the reaction which takes place during the burning of ethanol in air.

State whether human beings reproduce by sexual method or asexual method.

What is the nature of a lens whose power is, -4D?

What happens when ethanol is oxidised with alkaline potassium permanganate (or acidified potassium dichromate)? Write the equation of the reaction involved.

Name the mode of reproduction occurring in Amoeba.

Name an alloy of copper. State its chemical composition and any one use.

Which effect of current is utilised in an electric light bulb?