Department of Physics

The instrument that measures and records the relative humidity of air is

• • Hydrometer

  
  

• • Hygrometer

• Lactometer

• Barometer

The different colours of different stars are due to the variation of

• temperature

• Suppress

• density

• radiation of them

Woolen clothes keep the body warm because

• Wool increases the temperature of the body

• Wool is a bad conductor

• ool absorbs radiant heat from outer objects

• Wool rejects heat from the outer objects

While catching a ball, a player pulls down his hands to lower the

• force

• Momentum

• impulse

• catching time

Smog is a general pollutant where

• temperature is high

• temperature is low

• • air contains excess ammonia.

• • air contains excess SO₂.

Clothes keep us warm in winter because they

• supply heat

• do not radiate heat

• prevent air from contacting the body

• prevent the heat of the body from escaping

Which of the following is used in pencils

• Graphite

• Silicon

• Germanium

• Iron

Chemical formula for water is

• H2O2

• CO2

• H2O

• HNO3

Washing soda is the common name for

• Calisium carbonate

• Sodium carbonate

• Sodium bicarbonate

• Calisium bicarbonate

The hardest substance available on earth is

• Gold

• Iron

• Diamond

• Platinum