Conservation of Plants and Animals — Science STD 8 — Question

Which of the following are non-contact forces ? Magnetic force, Frictional force, Gravitational force, Muscular force, Electrostatic force.

Fishes are considered good for health. Give reason.

Discuss the characteristic properties of plastics.

Explain why, sometimes when we take off the woollen sweater or a polyester shirt in a dark room, we can see tiny sparks of light and hear a crackling sound.

What happens when the two plates of earth's crust moving in opposite directions slide past one another?

Explain how does a sound making object differ from one that is silent.

Write a paragraph in your own words on each of the following.
Preparation of soil

Name one natural and one artificial satellite of the Earth.

Name the most common application of the chemical effect of electric current.

In human females, each time during maturation and release of egg, the inner wall of uterus thickens. Is this thickening permanent ? Give reasons.