Name two events (other than earthquakes) which can cause tremors on the earth.

Name the scale on which the magnitude (or intensity) of an earthquake is expressed.

For what purpose is Richter Scale used?

In the context of an earthquake, which one is deep under the ground: focus or epicentre?

State whether the following statements are true or false :

(a) Like charges attract each other.

(b) A charged glass rod attracts a charged plastic straw.

(c) Lightning conductor cannot protect a building from lightning.

(d) Earthquakes can be predicted in advance.

(e) An earthquake of magnitude 2 on Richter Scale is ten times as strong as an earthquake of magnitude 1 on the same Scale.

(f) The plates of earth's crust are continuously moving.

(g) An earthquake is measured and recorded by using an instrument called electrocardiograph.