Which of the following is a commercial source of energy?

• Agricultural waste

• Dried dung

• Sun

• Sun

Addition of suitable impurities into semiconductor, is called

• Doping

• Mixing

• Forming

• Forming

Arsenic problem in India is primarily due to

• Overexploitation of coal in Bihar and Bengal

• Overexploitation of arsenopyrite in the hinterland

• Overexploitation of ground water in the affected areas

• Overexploitation of ground water in the affected areas

Green House Effect means

• Pollution in houses in tropical region

• Prevention of ultra-violet radiation by the ozone layer

• Trapping of solar energy due to atmospheric gases

• Trapping of solar energy due to atmospheric gases

Highest percentage of carbon is found in which form of coal?

• Anthracite

• Bituminous

• Peat

• Peat

The presence of air bubble in bloodstream is dangerous to life because

• Air combines with blood forming a complex

• The flow of blood increases manifold

• The flow of blood is obstructed

• The flow of blood is obstructed

Which of the following plays an important role in photosynthesis?

• Chloroplast

• Centrosome

• Tonoplast

• Tonoplast

The purest form of water in nature is

• Rain water

• Lake water

• River water

• River water

The component used for tuning a radio is basically a variable

• Resistor

• Condenser

• Inductor

• Inductor

Which of the following is not a donor atom?

• Phosphorus

• Antimony

• Arsenic

• Arsenic