231.

Who discovered Uranus?

• Sir Issac Newton

• William Henry Fox Talbot

• William Herschel

• Nicolaus Copernicus

What is the unit of calorific value?

• kN/kg

• kJ/kg

• kW/sec

• kCal/sec

According to the Central Pollution Control Board (CPCB), particulate size .........micrometers or less in diameter are responsible for causing the greatest harm to human health.

• 0.5

• 2.5

• 5

• 10

Fire Extinguishers emit which gas?

• Carbon monoxide

• Chlorine

• Carbon dioxide

• Nitrogen

A change in which no new substances are formed is called ...........

• Physical Change

• Chemical Change

• Rusting

• Galvanisation

The property of metal by which it can be drawn into wires is called ___________.

• maleability

• viscosity

• ductility

• tensile strength

............ is the number of deaths in the population during a given period.

• Natality

• Mortality

• Immigration

• Emigration

A change in which a substance undergoes a change in its physical properties is called ............

• Chemical Properties

• Physical Properties

• Chemical Change

• Physical Change

............ is the most ecologically relevant environmental factor.

• Water

• Temperature

• Light

• Soil

................ is obtained by evaporation of sea.

• Sugar

• Iron

• Salt

• Steel