Crop production and management — Science STD 8 — Question

What is air? Write the names of various constituents of air.

What will you observe when the metal top of an electroscope is touched with a plastic comb rubbed in dry hair? Give reason for your answer.

Which of the following animals undergo metamorphosis and which do not?
Cow, Butterfly, Silk moth, Humans, Frog, Housefly, Sparrow, Hen, Mosquito, Money.

What happens to the tail of a comet when it moves far away from the Sun?

Which will cause more friction: a rough surface or a smooth surface? Why?

Name the unit which is used to express distances between the various celestial bodies (like stars and planets).

How do you preserve cooked food at home?

Give two examples of situations where you push or pullto change the state of motion of objects.

What should we do if something like a dust particle or an insect gets into our eye?

Which effect of electric current is utilized for detecting the flow of current through a solution:

1. When a torch bulb is used?
2. When a compass is used?