41.
Cooking gas is a mixture of

42.
Thermal electricity is generated by using which of these ?

43.
Which of the following is the major constituent of LPG?

44.
Which variety of coal contains recognisable traces of the original plant material ?

45.
Which of the following processes is used for the production of Biodiesel ?

46.
The chief source of naphthalene is

47.
The gas that usually causes explosions in coal mines is

48.
Submarines move under water. They have engines that run on

49.
Which is the highest quality of hard coal?

50.
The main source of Naphthalene is