Physics Questions

During convection, cool and dense air falls through the warmer and less dense air. The warm air having less mass is being displaced by the cooler which is much heavy. Convection always involves the air rising through the atmosphere.

As it is said that density of gold is greater than that of density of silver, so silver occupies a greater volume than gold. So it has more upthrust from the water, although they both show the same weight under water, there is more silver present. Hence silver piece will weigh more.

Sea appears blue in colour due to the scattering of the rays when they hit water molecules

A modem is nothing but short for Modulator and Demodulator. It is used mostly for connecting to the internet.

A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves.

Gear Lapping is an operation after heat treatment. Gear lapping is the process of imparting a very fine finish and high degree of accuracy to gear teeth, by using a lapping tool and applying a fine-grained abrasive between a work material and a closely fitting surface, called a lapping plate.

A Light-year is a distance that light travels in the vacuum in one Julian year (365.25 days).

The light-year is a unit of length used to express astronomical distances. It is about 9.5 trillion kilometers or 5.9 trillion miles.