Previous Year Questions General Science for CDS & CAPF: 19th September

Previous year questions must be prepared when it comes to the preparation of CDS & CAPF examinations. Defenceadda is providing you with the previous year questions of General Science Section.

Q1. Fat can be separated from milk in a cream separation because of 
(a) Cohesive force
(b) Gravitational force
(c) Centrifugal force
(d) Centripetal force

Q2. Which one of the following is not result of surface tension? 
(a) Vapour formation above the liquid surface
(b) Convex shape of liquid meniscus
(c) Liquid rising in a capillary
(d) Spherical shape of mercury fallen on the floor

Q3. Hair of a shaving brush clings together when the brush is removed from water due to 
(a) Viscosity
(b) Surface tension
(c) Friction
(d) Elasticity

Q4. Consider the following statements 
1. Clear sky appears blue due to poor scattering of blue wavelength of visible light.
2. Red part of light shows more scattering than blue light in the atmosphere.
3. In the absence of atmosphere, there would be no scattering of light and sky will look black.
Which of the statements given above is/are correct?
(a) Only 1
(b) 1 and 2
(c) Only 3
(d) All of these

Q5. The most familiar form of radiant energy in sunlight that causes tanning and sun burning of human skin, is called 
(a) Ultraviolet radiation
(b) Visible radiation
(c) Infrared radiation
(d) Microwave radiation

Q6. Which one of the following substances is used in the manufacture of safety matches? 
(a) Red phosphorus
(b) White phosphorus
(c) Phosphorus trioxide (P203)
(d) Black phosphorus

Q7. Which one of the following is correct? Butter is 
(a) a supercoiled oil
(b) An emulsion
(c) a molecular solid
(d) None of these

Q8. Which one of the following is the softest? 
(a) Sodium
(b) Aluminum
(c) Iron
(d) Copper

Q9. Which one of the following properties changes with valency? 
(a) Atomic weight
(b) Equivalent weight
(c) Molecular weight
(d) Density

Q10. Which of the following has maximum density? 
(a) Chloroform
(b) Water
(c) Benzene
(d) Ice


S1. Ans.(c) 
Sol. Centrifugal force separates fat from milk.

S2. Ans.(a)

S3. Ans.(b)
Sol. When brush is taken out, the water film is formed between the hairs and they contract due to surface tension.

S4. Ans.(c)
Sol. The appearance of blue colour of sky is due to scattering of light which is not possible in absence of atmosphere.

S5. Ans.(a)
Sol. The tanning and sun burning of human skin is due to the harmful ultraviolet radiation from the sun.

S6. Ans.(a)
Sol. Red phosphorus is mostly used in the manufacture of safety matches.

S7. Ans.(d)
Sol. Butter is an example of a colloidal dispersion of a liquid in a solid i.e., gel.

S8. Ans.(a)
Sol. Alkali metals such as lithium, sodium and potassium are soft metals. These can be easily cut with a knife.

S9. Ans.(b)
Sol. Only equivalent weight changes with valency. Atomic weight, molecular weight and density does not change with valency.
Equivalent weight of the element = (Atomic weight)/(Valency )

S10. Ans.(b)
Sol. Water has the maximum density among these because chloroform, benzene and ice float on water.

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