CAPF (AC) 2016 (Paper-1) (Question 1-50)

Total Questions: 50

21. Which one of the following is the correct order of formation of geological systems in India in terms of their age? (Starting with the oldest)

(a) Dharwars - Aravallis - Vindhyans - Cuddapahs
(b) Aravallis - Dharwars - Cuddapahs - Vindhyans
(c) Vindhyans - Dharwars - Aravallis - Cuddapahs
(d) Cuddapahs - Vindhyans - Dharwars - Aravallis

Correct Answer: (b) Aravallis - Dharwars - Cuddapahs - Vindhyans

Solution:The Aravalli Range is the oldest range of Fold Mountains in India and metamorphosed sedimentary rocksystem. It was formed 4 billion to 1 billion years ago. Dharwarswere formed between 3.6 and 2.5 billion years ago.

The Cuddapah and Vindhyan rock systems were formed1400-600 million years ago. They are formed by the erosion and deposition of Archean and Dharwar rocks. The "Vindhyan Supergroup" was formed 1.6 to 1.7 billion years ago. Itis one of the largest and thickest sedimentary successions in the world. Therefore, the correct option is (b).

22. A change of state directly from solid to gas without changing into liquid state is called :

(a) Fusion
(b) Sublimation
(c) Diffusion
(d) Emulsion

Correct Answer: (b) Sublimation

Solution:The process of the conversion of a substance from the solid to the gaseous state without its becoming liquid is known as sublimation. The process of joining two or more things together to form a single entity is known as fusion.

The net movement of any matter from a region of higher concentration to a region of lower concentration is known as diffusion. The process in which one liquid (the dispersed phase) is dispersed in the other (the continuous phase) is known as an emulsion. Therefore, the correct option is (b).

23. Water at 273 K is less effective in cooling than ice at the same temperature. It is because :

(a) water is difficult to handle
(b) water at 273 K has less energy than ice at the same temperature
(c) water at 273 K has more energy than ice at the same temperature
(d) water is not a cooling agent

Correct Answer: (c) water at 273 K has more energy than ice at the same temperature

Solution:To achieve room temperature, the ice at 273 K will absorb latent heat as well as thermal energy. Water at a temperature of 273 K would just absorb heat energy to achieve room temperature. Thus, water at 273 K will absorb less environmental heat energy than ice at 273 K. Therefore, ice at 273 K is more effective in cooling than water at the same temperature. Therefore, the correct option is (c).

24. Which one of the following statements is not correct?

(a) The rate of evaporation depends on temperature
(b) The rate of evaporation does not depend on surface area exposed to the atmosphere but on volume of the liquid
(c) The rate of evaporation depends on humidity of the surroundings
(d) The rate of evaporation depends on the wind speed

Correct Answer: (b) The rate of evaporation does not depend on surface area exposed to the atmosphere but on volume of the liquid

Solution:The rate of evaporation depends upon the temperature, humidity of the surroundings, and wind speed. When there is a large surface area and exposed to the atmosphere, it would react to change in temperature and pressure.

On the increase in surface area, the rate of evaporation also increases. This increases the probability of liquid molecules evaporating as the surface area rises. There is indirectly proportional to the humidity. Therefore, the correct option is (b).

25. Which one of the following is not a colloid?

(a) Milk
(b) Mud
(c) Butter
(d) Boric acid

Correct Answer: (d) Boric acid

Solution:Boric acid, also called hydrogen borate, boracic acid, and orthoboric acid is a weak, monobasic Lewis acid of boron. It has the chemical formula HBO. The size of the particles in a colloidal solution is range from 1 to 1000 nanometres.

An effect of scattering of light in colloidal dispersion is known as the Tyndall effect. This effect was discovered by an Irish physicist, John Tyndall. A true solution does not show Tyndall effect. Therefore, the correct option is (d).

26. Match List-I with List-II and select the correct answer using the code given below the Lists:

List-I (Isotope)	List-II (Application)
A. Carbon	1. Treatment of goitre
B. Cobalt	2. Calculation of age of the earth
C. Iodine	3. Treatment of cancer
D. Uranium	4. Fuel in nuclear reactors

Code:	A	B	C	D
(a)	2	3	1	4
(b)	2	1	3	4
(c)	4	1	3	2
(d)	4	3	1	2

Correct Answer: (a)

Solution:The isotope of carbon, (carbon-14) is used to calculate the age of the earth, with a half-life of 5,730 years. Iodine (Iodine-131) is used in the treatment of goitre.

It reduces the size of the goitre, but eventually may also cause an underactive thyroid gland. The gamma rays from the radioisotope Cobalt (cobalt-60) is used to treat cancer. Uranium (U-235) is used as a fuel in nuclear reactors. Therefore, the correct option is (a).

27. A device can write 100 digits in 1 minute. It starts writing natural numbers. The device is stopped after running it for half an hour. It is found that the last number it was writing is incomplete. The number is :

(a) 3000
(b) 3001
(c) 1026
(d) 1027

Correct Answer: (d) 1027

Solution:Number of digits from 1 - 9 = 9

Number of digits from 10 - 99 = 2 × 90 = 180

Number of digits from 100 - 999 = 3×900 = 2700

Number of digits = 9+189 +2700 = 2889

Total number of digits = 3000

(∴ In 1 minute device can write 100 digits In 30 minutes device can write 2000 digits)

Remaining digits = 3000 - 2889 = 111

We have to make it write the number from 1000 to 1026 total numbers = 27

Digits need to write these 27 numbers = 27 × 4 = 108.

Now he left with 111-108 = 3

Last number which has to be written = 1027

⇒ 1 = 109th digit

⇒ 2 = 111th digit

⇒ 0 = 110th digit

⇒ 7 = 112th digit

∴ 1027 is the incomplete number.

28. A circular coin of radius 1 cm is allowed to roll freely on the periphery over a circular disc of radius 10 cm. If the disc has no movement and the coin completes one revolution rolling on the periphery over the disc and without slipping, then what is the number of times the coin rotated about its centre?

(a) 10
(b) 10.5
(c) 11
(d) 12

Correct Answer: (c) 11

Solution:Circumference of the coin = 2 × (1) ⇒ 2π

Circumference of the disc = 2π × (10) ⇒ 20π

Total number of times the coin rotated about its centre

= 20π/2π = 10 times

29. Which one of the following is different from the remaining three?

(a) Triangle
(b) Square
(c) Circle
(d) Ellipse

Correct Answer: (a) Triangle

Solution:Triangle is different from the remaining three as, There is no sub-division of all the three except triangle. Triangle is sub-divided in equilateral, isosceles, right angle, etc.

30. Which one of the following inequalities is always true for positive real numbers x, y?

(a) xy > x + y
(b) (x+y) < (x + y)²
(c) x + y < x² + y²
(d) 1 + x + y < (1 + x + y)²

Correct Answer: (b) (x+y) < (x + y)²

Solution:In this we can just check it by putting the random values in all the options.

Let's put x=1/2 and y=1/2, in the first option,

L.H.S will be ¼ and R.H.S will be 1, so it does not satisfy.

In second option L. H. S will be 1 and R.H.S will be 1 and it does not satisfy In third option L.H.S will be 1 and R.H.S will be 1/2. In 4th option L.H.S will be 2 and R.H.S will be 4 and that satisfy the inequality.

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