Sour taste of lemon is due to the presence of which of the following ?
1). Citric acid
2). Acetic acid
3). Oxalic acid
4). Formic acid
1. Which of the following is used as filler in tyre of rubber ?
2. Impure camphor is purified by
4. Gunpowder consist ofa mixture of
5. The movement inside the Earth's crust is studied by which of the following ?
6. This group of alumino silicate minerals is widely used In making electrical insulators
7. Highest percentage of carbon is found in which form of coal?
8. The phenomenon of radioactivity was discovered in 1898 A. D. by-