21: Which one of the following types of glass can cut off ultraviolet rays ?
(a) pyrex glass
(b) Soda glass
(c) Crookes glass
(d) Jena glass
22: Two men A and B have different basic salaries but get equal emoluments. Their allowances are 65% and 80% of their basic salaries respectively. The ratio of their basic salaries is:
(a) 13 : 16
(b) 8 : 9
(c) 12 : 11
(d) 80 : 65
23: To which one of the following processes is term CMYK related ?
(a) Railway Signalling
(b) Navigation
(c) Offset printing
(d) Electronic voting machine
24: Which of the following is true about the Bats?
1. Bats are mammals
2. Bats have wings which are actually the modified forelimbs
3. Bats are nocturnal in habit
(a) 1, 2 & 3
(b) 2 & 3
(c) 1 & 3
(d) 1 & 2
25: In which of the following activities are Indian Remote Sensing (IRS) satellites used?
1. Assessment of crop productivity
2. Locating groundwater resources
3. Mineral exploration
4. Telecommunications
5. Traffic studies
Select the correct answer using the code given below.
(a) 1, 2 and 3 only
(b) 4 and 5 only
(c) 1 and 2 only
(d) 1, 2, 3, 4 and 5