20000+ Important MCQs for AIR FORCE

61) The known forces of nature can be divided into four classes, viz, gravity, electromagnetism, weak nuclear force and strong nuclear force. With reference to them, which one of the following statements is not right?

62) Nitrogen in water is commonly found in the form of

63) 'Atomic theory' of matter was given by

64) A magnetic field does not interact with

65) Golden view of sea shell is due to

66) With reference to 'fly ash' produced by the power plants using coal as fuel. Which among the given statements is/are right? 
1. Fly ash can be used in the production of bricks for building construction. 
2. Fly ash can be used as a replacement for some of the Portland cement contents of concrete.
3. Fly ash is made up of silicon dioxide and calcium oxide only, and does not contain any toxic elements. 
Select the right answer using the code given below

67) Ability of the eye to see objects at all distances is called

68) When quick lime is added to water

69) Setting of plaster of paris involves

70) Which of the following one of the following minerals is found in Monazite sand -