CAPF (AC) 2015 (Paper-1) (Question 101-125)

Total Questions: 25

21. Heavy water of an atomic reactor is :

Correct Answer: (d) an oxide of heavier isotope of hydrogen
Solution:Heavy water is also known as deuterium oxide (D₂O). It has a unique atomic structure and properties coveted for the production of nuclear power and weapons. It is a form of water that contains a large amount of hydrogen isotope deuterium (heavy hydrogen). It may be deuterium protium oxide (DHO) or deuterium oxide (D₂O). Heavy water is used in certain types of nuclear reactors, where it acts as a neutron moderator to slow down neutrons. Therefore, option (d) is correct.

22. In a radioactive decay of a nucleus, an electron is also emitted. This may happen due to the fact that :

Correct Answer: (b) an electron is created at the time of conversion of a neutron into proton
Solution:Beta-decay is a type of radioactive decay in which a proton is transformed into a neutron or vice versa inside the nucleus of the radioactive sample. In other words, we can say that in the process two neutrons are simultaneously transformed into two protons.

It takes place in the presence of weak interaction. Beta particles are high energy electrons that move at high speed. Therefore, the correct option is (b).

23. (Question 123 to 125): The next three (03) items have two premises and two conclusions. If the premises are assumed to be true (irrespective of factuality); then, in respect of each of the items given below, which of the following conclusions follow logically?

Premises: All metals are grey in colour. Some metals are heavy.

Conclusion:

I. All heavy metals are grey in colour.

II. All light metals are not grey in colour.

Correct Answer: (a) Only I

24. .

Premises: All film stars are playback singers. All film directors are film stars.

Conclusion :

I. All film directors are playback singers.

II. Some film stars are film directors.

Correct Answer: (c) Both I and II
Solution:All film directors are playback singers. True: As all the film directors are film stars and all film stars are playback singers. Some film stars are film directors. True: As all the film directors are film stars. Hence, both I and II follow. Therefore, option (c) is correct.

25. .

Premises: All apples are golden in colour. No golden coloured things are cheap.

Conclusion :

I. All apples are cheap.

II. Golden coloured apples are not cheap.

Correct Answer: (b) Only II
Solution:The first premise is universal affirmative, i.e., (A-type). The second premise is Sa universal negative, i.e., (E-type). All mangoes are golden in colour. It implies that all mangoes without an exception are golden in colour. No golden coloured things are cheap. Thus, Conclusion II follows. Therefore, option (b) is correct.