The stars twinkle in the night because

  1. They emit light intermittently
  2. The earth’s atmosphere absorbs light intermittently
  3. The refractive index of the air in the atmosphere fluctuates
  4. None of These

Epidemiology means

  1. Study of epidemic disease
  2. Study of deficiency disease
  3. Study of medicine
  4. None of These

Green house effetcs means

  1. Trapping of solar energy due to atmospheric carbon dioxide
  2. Trapping of solar energy due to atmospheric oxygen
  3. Pollution in houses in tropical region
  4. None of these

Heavy water consists of

  1. Heavy oxygen and heavy hydrogen
  2. Oxygen and heavy hydrogen
  3. Heavy oxygen and hydrogen
  4. None of these

DNA is

  1. Acetic Acid
  2. A class of nucleic acids
  3. Citric Acid
  4. None of these

The kidneys in the human body

  1. Regulate the water balance in the body
  2. Regulate the concentration of the salts in blood and of the reaction of the blood
  3. Execute waste products and any excess of salts
  4. All of above

Dynamo is a device that converts

  1. Mechanical energy into electrical energy
  2. Electrical energy into mechanical energy
  3. Alternating current into direct current
  4. None of these