Part – B (General Studies) NDA/NA SOLVED PAPER 2018 (II) (51 to 100)

Total Questions: 50

11. Which one of the following is a waterborne disease?

Correct Answer: (a) Jaundice
Solution:

Jaundice is caused by microbial infection presnet in water and food items.

12. The atomic number of an element is 8. How many electrons will it gain to form a compound with sodium?

Correct Answer: (b) Two
Solution:

13. A sample of oxygen contains two isotopes of oxygen with masses 16µ and 18 µ respectively. The proportion of these isotopes in the sample is 3 : 1. What will be the average atomic mass of oxygen in this sample?

Correct Answer: (d) 16.5 µ
Solution:

14. Which one of the following is a heterogeneous mixture?

Correct Answer: (c) Milk
Solution:

A mixture that does not have uniform composition is called heterogeneous mixture.
Out of the given compounds, milk is a heterogeneous mixture of fats, carbohydrates, proteins etc. dispersed in water.

15. What is the formula mass of anhydrous sodium carbonate? (Given that the atomic masses of sodium, carbon and oxygen are 23µ,12 µ and 16 µ respectively).

Correct Answer: (b) 106 µ
Solution:

16. Which one of the following is called ‘syngas’?

Correct Answer: (c) CO(g) + H₂g
Solution:

Syngas or synthesis gas is mixture of Carbon monoxide (CO) gas and Hydrogen (H₂ ) gas. It may also consist of Carbon Dioxide (CO₂) gas. It is used as a fuel gas in various industries.

17. The frequency of ultrasound waves is:

Correct Answer: (d) greater than 20 kHz
Solution:

Ultrasonic waves range above 20 kHz which is above the audible range of human ears.

18. The magnetic field strength of a current carrying wire at a particular distance from the axis of the wire:

Correct Answer: (a) depends upon the current in the wire
Solution:

19. A stainless steel chamber contains Ar gas at a temperature T and pressure P. The total number of Ar atoms in the chamber is n. Now Ar gas in the chamber is replaced by CO₂ gas and the total number of CO₂ molecules in the chamber is n/2 at the same temperature T. The pressure in the chamber now is P’. Which one of the following relations holds true? (Both the gases behave an ideal gases):

Correct Answer: (c) P′ = P/2
Solution:

20. Which one of the following is the correct relation between Å and nm?

Correct Answer: (b) 1 nm = 10 Å
Solution:

1 Å = 0.1 nm
⇒ 10 Å = 1 nm