Which of the following is a greenhouse gas

• Chlorofluoro carbon
• Carbon
• Calcium
• None of these
Correct Option: A  [ Chlorofluoro carbon ]

Remark: Chlorofluorocarbons (CFCs) are considered greenhouse gases due to their ability to trap heat in the Earth's atmosphere.

Which one of the following organs is the main respiratory organ of whale?

• Integuments
• Gills
• Lungs
• Trachea
Correct Option: C  [ Lungs ]

Remark:

A fuse wire has :

• high resistance and high melting point
• low resistance and high melting point
• low resistance and low melting point
• high resistance and low melting point
Correct Option: D  [ high resistance and low melting point ]

Remark:

A transformer is used to :

• Increase or decrease D.C voltage
• Increase or decrease A.C voltage
• Convert A.C to D.C
• Convert D.C into A.C
Correct Option: B  [ Increase or decrease A.C voltage ]

Remark:

Which type of fire extinguisher is used for petroleum fire?

• Powder type
• Liquid type
• Soda acid type
• Foam type
Correct Option: A  [ Powder type ]

Remark:

What chemicals are used in fire extinguishers used in houses and offices ?

• Water, potassium bicarbonate and fluorocarbon
• Water, calcium hydroxide and chlorofluorocarbons
• Water, potassium hydroxide and chlorobenzene
• None of these
Correct Option: A  [ Water, potassium bicarbonate and fluorocarbon ]

Remark:

The pH of human blood is:

• 7.2
• 7.8
• 6.6
• 7.4
Correct Option: D  [ 7.4 ]

Remark:

The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is:

• Argon
• Xenon
• Helium
• Krypton
Correct Option: C  [ Helium ]

Remark:

A piece of ice is ?oating in a beaker containing water. When whole of the ice melts:

• the level of water will come down.
• the level of water will come up.
• the level of water will first rise and then fall.
• the level of water will remain the same.
Correct Option: D  [ the level of water will remain the same. ]

Remark:

Which one of the following sets of Elements was primarily responsible for the origin of life on the earth?

• Hydrogen, Oxygen, Carbon, Sodium
• Oxygen, Carbon, Calcium, Phosphorus
• Carbon, Hydrogen, Oxygen, Nitrogen
• Carbon, Hydrogen, Nitrogen, Potassium
Correct Option: C  [ Carbon, Hydrogen, Oxygen, Nitrogen ]

Remark: