In arc welding, Argon is used because of 

• Low reactivity with metal

• Ability to lower the melting point of the metal

• High flammability

• High flammability

The minimum short-term natural hazard is

• blizzard

• earthquake

• volcanic eruption

• volcanic eruption

The liberation of oxygen during photosynthesis is due to

• hydrolysis of carbohydrates

• photolysis of water

• reduction of CO₂

• reduction of CO₂

Formic acid is produced by ..............

• White ants

• Cockroaches

• Red ants

• Red ants

Which of the following is the cleanest source of energy?

• Biofuel

• Fossil Fuel

• Nuclear power

• Nuclear power

Which of the following fibres is considered as the strongest natural fibre?

• Cotton

• Jute

• Wool

• Wool

Ozone saves the biosphere by absorbing high energy radiations called .................

• Infra-red (IR)

• Gamma rays

• Ultraviolet rays (UV)

• Ultraviolet rays (UV)

108.

In absence of the earth's atmosphere, sky would appear .............

• blue

• deep red

• white

• white

Silica gel is a

• moisturizer

• flavouring agent

• drying agent

• drying agent

Chernobyl disaster is the result of pollution by _______________

• Oil spill

• Acid rain

• Carbon dioxide

• Carbon dioxide