General Knowledge (NDA/NA SOLVED PAPER 2023) (51 to 100)

Total Questions: 50

31. In which one of the following layers of the atmosphere all weather phenomenon occur?

Correct Answer: (b) Troposphere
Solution:Troposphere is the layer of atmosphere where all weather phenomenon occur. It is the lowest layer of earth's atmosphere, its average height is 13km and its lowest height is at poles which is 8 km and maximum height 18 km at the equator.

32. In which one of the following states 'Roopkund' lake is located?

Correct Answer: (d) Uttarakhand
Solution:Roopkund is located the lap of Trishulmassif in the Himlayas at a height of 5,020 metres (16,470 ft). This lake is locally known as Mystery Lake or Skeleton Lake beacuse the hundreds of ancient human skeletons found at the edge of the lake.

33. Ram records the odometer readings of his car for the distance covered from 2000 km at the start of his journey and 2400 km at the end of the journey after 8 hours. What is the average speed of the car ?

Correct Answer: (a) 50 km/h
Solution:(a)

34. Ms. Rani decides to convert her AC generator into a DC generator. Which one of the following she would need to use?

Correct Answer: (a) A split-ring type commutator
Solution:An AC generator can be converted in to a DC generator by using a split ring type commutator which helpsin maintaining a connection between the moving rotor and stator.

35. Ramesh cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using a lens of power

Correct Answer: (b) -0.5 D
Solution:This condition is know as near sightedness. This defect can be corrected by using the concave laws of power -0.5 D.

36. Which of the following statements are correct about the electrical resistance and resistivity of a wire?

1. Both quantities depend on the area of cross-section of the wire
2. Both depend on the temperature
3. Resistance of the wire is directly proportional to the resistivity of the wire
4. Resistivity of the wire is directly proportional to the length of the wire
Select the correct answer using the code given below :

Correct Answer: (c) 2 and 3
Solution:Resistance isinversely proportional to cross-sectional area but resistivity does not depend on area of cross-section as it has constant area of 1m².
Resistance of a wire is directly proportional to 99 length of wire whereas resistivity does not depend on length of wire because length of wire is kept constant, i.e. 1m.

37. A liquid is heated up to a certain temperature. Which one of the following situation would correspond to the boiling of the liquid?

Correct Answer: (a) When atmospheric pressure becomes equal to the vapour pressure
Solution:When atmospheric pressure becomes equal to the vapour pressure.

38. Which one of the following is NOT an example of organic compound?

Correct Answer: (a) Ammonium cyanate
Solution:Ammonium cyanate is an in organic compound whereas all other all organic compound. Urea is the first organic compoundto be developed in laboratory Friedrich Wöhler in 1828 which is called The Wöhler synthesis.

39. Which one of the following acid is used by goldsmith for cleaning of gold and silver articles ?

Correct Answer: (b) Nitric acid
Solution:Nitric acid (HNO₃), is a very reactive, highly corrosive, strong oxidizing agent but it does not react with less reactive metals like gold and silver hence it is used by goldsmiths for cleaning gold and silver articles. Its is also used in production of fertilizers, making of dyes, in school laboratory and as an oxidizer in liquid fueled rockets.

40. What is the action of litmus on ethanol?

Correct Answer: (a) Litmus is neutral towards ethanol
Solution:Litmus is neutral towards ethanol i.e. its colour does not change on treating it with ethanol / Ethyl alcohol (C₂H₅OH) because OH group attached to it does not dissociate as OH- ion which is responsible for change in colour.