Force and Pressure — PHYSICS STD 8 — Question

When does a force do work?

During dispersion of white light, which colour :-deviates most

Write the correct statement :
In order to produce an echo, the minimum distance between the source of sound and the reflecting body should be 14 m.

Write the correct statement :
A ray of light is incident perpendicularly on a glass slab. The angle of incidence is 90°.

What is the importance of above phenomenon in the formation of weather?

State the boiling point of water.

Write the correct statement :
When the piston of common water pump is raised its piston valve opens.

Write all the colours of spectrum in proper order, starting from red colour.

When does a force perform work?

Define the following :-Fusion point