2536: In an objective test there are 60 questions. Each question carries four alternative answers only one of which is correct. Suppose A and B are two candidates both of whom know correct answers to 30 questions. A answers only 30 questions while B answers all 60 questions choosing answers at random for those he does not know the answers of. If each question carries a mark of 1 and no negative marks are awarded, the marks obtained by B are expected to be larger than those obtained by A by
(a) 0
(b) 15
(c) 5
(d) 7.5
2537: Which of the following are some important pollutants released by steel industry in India?
1. Oxides of sulphur
2. Oxides of nitrogen
3. Carbon monoxide
4. Carbon dioxide
Select the correct answer using the code given below.
(a) 1, 3 and 4 only
(b) 2 and 3 only
(c) 1 and 4 only
(d) 1, 2, 3 and 4
2538: Which one of the following polymers is widely used for making bullet proof material ?
(a) Polyvinyl chloride
(b) Polyamides
(c) Polyethylene
(d) Polycarbonates
2539: A person earns Rs. 2000 per month over and above his salary as additional charge allowance. However, 30% of this additional income will be deducted as additional income-tax at source. If the person would deposit Rs. 1000 per month on a long-term saving fetching 12% interest his tax liability on the additional allowance would reduce to 10%. What is the effective interest for this person for money invested in the long-term savings scheme ?
(a) 12%
(b) 18%
(c) 19%
(d) 20%
2540: India carried out its first underground nuclear explosion at:
(a) Thumba
(b) Pokhran
(c) Trombay
(d) Khemkaran