GK-General Science Question and Answer
GK-General Science Question and Answer
41. The two elements that are frequently used for making transistors are
- boron and aluminium
- silicon and germanium
- iridium and tungsten
- niobium and columbium
44. In fireworks, the green flame is produced because of
- sodium
- barium
- mercury
- potassium
45. Permanent hardness of water can be removed by adding
- chlorine
- washing soda
- potassium permanganate
- bleaching powder
47. LPG consists of mainly
- methane, ethane and hexane
- ethane, hexane and nonane
- methane, hexane and nonane
- methane, butane and propane
49. Production of chlorofluorocarbons (CFC) gas which is proposed to be banned in India, is used in which of the following domestic products?
- Television
- Refrigerator
- Tube light
- Cooking gas