Combustion and Explosives

he picture below shows two cases in which a person is trying to burn the paper cup. In case 1, the cup has water in it and in case 2, it is empty and dry. Identify in which of the cases the paper will burn.

• Case 1

• case 2

• Both case 1 and case 2

• D. The paper doesn’t burn in both the cases.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS3-3

Which type of fire extinguisher should be used on a fire involving flammable liquids such as grease or oil?

• Water
• Carbon Dioxide 
• Dry Chemical
• Foam

Water is not used to control fires involving electrical appliances.

• False
• True

Which of the following fuel has highest calorific value?

• Wood
• coal
• Hydrogen
• petrol

Tags

NGSS.MS-PS3-4

If a flame is giving off smoke, this type of combustion is occurring...

• Complete combustion

• Incomplete combustion

Moderately hot zone in a candle flame

• outer zone

• middle zone

• innermost zone

• wax candle

Which substance give heat and light after combustion

• Flame

• Fuel

• Combustion

• None of these

Coal burns with ____________________________

• Flame

• Only glow

• Both flame and glow

• None of these

Burning of charcoal in a closed room will produce

• Carbon dioxide

• Nitrogen dioxide

• Carbon monoxide

• Sulphur dioxide

Tags

NGSS.MS-PS1-5

The substances which have very low ignition temperature will

• Catch fire easily

• Will not catch fire

• Catch fire after some time

• None of these