A. I, II, III and IV
B. I, III and IV
C. I, II and IV
D. I and IV
Which one of the following noble gases is used in miner's cap lamps
Which of the following is not a peroxy acid
Calorific value of producer gas is low because of
Which of the following is used for making optical instruments ?
CFCl<sub>3</sub> is responsible for the decomposition of ozone to oxygen. Which of the following reacts with ozone to form oxygen ?