CAPF (AC) 2022 (Paper-1) (Question 1-50)

Total Questions: 50

31. A number is 124 more than its one-third. What is that number?

(a) 194
(b) 180
(c) 189
(d) 186

Correct Answer: (d) 186

Solution:

32. A car travels 3/4th of the distance at a speed of 60 km/hr and remaining 1/4th of the distance at a speed of v km/hr. If the average speed for the full journey is 50 km/hr, then the value of v is

(a) 40
(b) 30
(c) 100/3
(d) 35

Correct Answer: (c) 100/3

Solution:

33. Suppose A and B can complete a work together in 10 days. If B alone can complete the work in 15 days, then in how many days can A alone finish the work?

(a) 20 days
(b) 24 days
(c) 25 days
(d) 30 days

Correct Answer: (d) 30 days

Solution:Time taken by A to complete the work

= (15 × 10) / (15 - 10)

= 30 days

34. If the average of the first four of five numbers in decreasing order is 25 and the average of the last four numbers is 20, then what is the difference between the first and the last number?

(a) 5
(b) 10
(c) 15
(d) 20

Correct Answer: (d) 20

Solution:Difference between first and last number.

= 4 × [(Average of first four) - Average of last four]

= 4[25 - 20] = 20 .

35. Borax is prepared from

(a) calcium carbonate
(b) magnesium carbonate
(c) potassium carbonate
(d) sodium carbonate

Correct Answer: (d) sodium carbonate

Solution:Borax is prepared from Sodium Carbonate( (Na₂ CO₃) . Borax is a powdery white substance, also known as sodium borate, sodium tetraborate, or disodium tetraborate. It's widely used as a household cleaner and a booster for laundry detergent. It's a combination of boron, sodium, and oxygen.

Na₂ [B₄ O₅ (OH)₄] 8H₂ O

IUPAC ID: Sodium tetraborate decahydrate.

36. Cinnabar is an ore of

(a) mercury
(b) zinc
(c) copper
(d) lead

Correct Answer: (a) mercury

Solution:Cinnabar is an ore of mercury.

Cinnabar is a toxic mercury sulfide mineral with a chemical composition of HgS. Cinnabar is a hydrothermal mineral that precipitates from ascending hot waters and vapors as they move through fractured rocks.

37. White gold is an alloy of

(a) gold, nickel and palladium
(b) gold, cobalt and palladium
(c) gold, titanium and platinum
(d) gold, magnesium and palladium

Correct Answer: (a) gold, nickel and palladium

Solution:White Gold is an alloy of gold, nickel and palladium. Utilised for its beauty and corrosion resistance, gold is too soft in its pure form for many practical applications. It is therefore hardened by the addition of other metals, such as copper, silver, nickel, palladium and zinc. This combination of metals is called an alloy.

38. Hydrogenation of alkenes can be carried out in the presence of

(a) copper
(b) zinc
(c) aluminium
(d) nickel

Correct Answer: (d) nickel

Solution:Hydrogenation of alkenes can be carried out in the presence of nickel.

Hydrogenation is a chemical reaction between molecular hydrogen (H₂) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic compounds.

39. Calcium oxide reacts with water to produce slaked lime. It is an example of

(a) combination reaction
(b) decomposition reaction
(c) oxidation reaction
(d) addition reaction

Correct Answer: (a) combination reaction

Solution:Chemical oxide reacts with water to produce slaked lime. It is an example of Combination Reaction.

A Combination reaction is a reaction where two or more elements or compounds combine to form a single compound. e.g. Ca O + H₂O → Ca (OH)₂ + Heat Such reactions are represented by equations of the following form: X + Y → XY.
A decomposition reaction occurs when one reactant breaks down into two or more products.
This can be represented by the general equation: AB →A+B.
The reaction in which oxygen combines with other elements or compounds is known as an oxidation reaction. For example, burning of hydrogen is an oxidation process in which hydrogen combines with oxygen to form water.
An addition reaction, in organic chemistry, is in its simplest terms an organic reaction where two or more molecules combine to form a larger one.

40. The atomic radius of hydrogen atom is

(a) 37 nanometer
(b) 37 picometer
(c) 17 picometer
(d) 57 picometer
(*)

Correct Answer: (*)

Solution:Atomic radius is the measure of the distance between the center of the nucleus to the boundary of the electrons surrounded by it. The Hydrogen atom has an atomic number 1 and a standard atomic weight of 1.008. Its atomic radius is measured to be 53 pm where p m stands for picometer measurement.

« Previous 1 2 345 Next »