Water: A Precious Resource — Science STD 7 — Question

Briefly tell that how many reflected rays can be obtained from a single incident ray in respect of a plane mirror?

In which type of toilets, human excreta is treated by earthworm?

State whether the following statements are true or false. In case a statement is false, write the corrected statement in your notebook. Iron pipes coated with zinc do not get rusted easily. (True/ False)

How food is pushed down from mouth to stomach?

What are acids?

Paheli while moving in a forest observed that there was no noise pollution, though lots of heavy vehicles were passing from the nearby highway. Explain why?

Explain the reason for wrapping of ice in gunny bags.

What is the colour of water in which potassium permanganate (KMnO4) is dissolved?

Define time period of a pendulum.

State the consequence when one food chain is disturbed in an ecosystem.