Physics
1-Boyle Law holds good for any gas at Low temperature and high pressures
2- The plastic material commonly used for making gear wheels is Nylons
3-When the Barometer reading suddenly dips, it is an indication of Storm
4-The substance which conducts current in the solid state is graphite
5-Holography is a technique of recording a permanent three dimensional photograph of a given single colour or a multicolour
6- Micro waves is used for communication by artificial satellites
7-Anthracite coal produces most heat per unit
8- Surface Tension in a liquid is due to cohesive force between molecules
9-A bolometer is a device for measuring the power of incident electromagnetic radiation with a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley.
10-Pipelines in cold countries often burst in winter because water freezes and expands in its volume
11-The density of a gas is maximum at low temperature, high pressure
12-Tungsten is used for the manufacture of the filament of an electric bulb, because it has very high melting point
13-When a body is taken from earth to moon weight changes but mass remains same
14-A dynamo is a device which converts mechanical energy into electrical energy
15-Adiabatic Demagnetisation principle is used to produce low temperatures
16-The instrument used to see the distant objects on the Earth is Terrestrial Telescope
17-A concave lens always forms an image which is virtual and erect
18-A photo-electric cell converts light energy to electrical energy
19-Two stones of different masses are dropped simultaneously from the top of a building, both the stones reach the ground at the same time
20- A mirage occurs because of total internal reflection by layer of air
21-A soap bubble shows colors when illuminated with white light. This is due to Interference
22-The device used to change the speed of an electric fan is Regulator