NDA/NA SOLVED PAPER 2016-I (GENERAL KNOWLEDGE)

Total Questions: 100

21. The S.I. unit of acceleration is

Correct Answer: (b) ms⁻²
Solution:The SI unit of acceleration is the metre per second squared (ms⁻²).

22. An atom of carbon has 6 protons. Its mass number is 12. How many neutrons are present in an atom of carbon?

Correct Answer: (b) 6
Solution:Mass number = number of proton + number of neutron
12 = 6 + number of neutron
12 - 6 = number of neutron
number of neutron = 6

23. Which one of the following is a reduction reaction?

Correct Answer: (c)
Solution:Mercuric oxides got reduced to mercury and its oxidation number changes from +2 to 0. Whereas in other reaction are showing oxidation reaction.

24. Which of the commonly used household item(s) release Bisphenol A(BPA) which is an endocrine disruptor and bad for human health?

1. Steel utensils
2. Plastic coffee mugs
3. Aluminium utensils
4. Plastic water strorage bottles

Select the correct answer using the code given below:

Correct Answer: (c) 2 and 4 only
Solution:Endocrine disruptors are chemicals (Bisphenol A) released from coffee mugs plastic water storage bottles, that may interfere with the body's endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife.

25. The Nagarjuna Sagar Project is located on which one of the following rivers?

Correct Answer: (b) Krishna
Solution:Nagarjuna Sagar Dam is located 150 kilometers from Hyderabad, on the Krishna River.

26. Consider the following statements:

1. Rajmahal highlands consist of lava flow deposits.
2. Bundelkhand gneiss belong to the oldest Achaean rocks of India.

Which of the statements given above is/are correct?

Correct Answer: (c) Both 1 and 2
Solution:Rajmahal hills of Jharkhand is the type area of this province. Multiple layers of solidified lava made 608 m (1,995 ft) thick Rajmahal hill. The chief characteristic of the geology and rocks of India arid-zone is noticed in its remarkable succession of pre-Cambrian rocks which go far down towards the base of the Archaean. This sequence commences for the Bundelkhand gneiss, which is one of the oldest granites exposed anywhere upon the earth' surface.

27. An object is placed at the centre of curvature of a concave mirror of focal length 16 cm. If the object iis shifted by 8 cm towards the focus, the nature of the image would be

Correct Answer: (a) real and magnified
Solution:Image formed by concave mirror when object is placed between centre of curvature and focus will be real and magnified.

28. A pencil is placed upright at a distance of 10 cm from a convex lens of focal length 15 cm. The nature of the image of the pencil will be

Correct Answer: (d) virtual, erect and magnified
Solution:Image formed by covex mirror when object is placed between focus and optical centre will be virtual, erect and magnified.

29. Which one of the following is a conventional energy source?

Correct Answer: (d) Biomass energy
Solution:Biomass energy is considered as conventionl energy source as it has been used from ancient times.

30. Which one of the following oxides of nitrogen is known as 'anhydride' of nitric acid?

Correct Answer: (d) N₂O₅
Solution:Two oxides of nitrogen are acid anhydrides; that is, they react with water to form nitrogen-containing oxyacids. Dinitrogen trioxide is the anhydride of nitrous acid, HNO2, and dinitrogen pentoxide is the anhydride of nitric acid, HNO3.