Test : General Science - 9 - Defence MCQ

White blood cells (WBC) bring out the function of body defence.

Beri-Beri is not insect borne disease. It is caused by the deficiency of vitamin-B_1 or thiamine.

Nitric acid is used in the production of fertilizers. The principal chemical produced form nitric acids ammonium nitrate, sulphuric acid is used in the production of explosives like TNT, nitroglycerine, gun cotton, etc. 

Baking soda has sodium bicarbonate as the chief constituent. It decomposes on heating giving carbon dioxide. This causes dough, cakes, biscuits etc. to expand and become light. 

In a pressure cooker while cooking pressure increases due to which boiling point of water also increases as P ∝ T.  

Velocity of raindrop increases until it reaches the terminal velocity.

X-rays cannot be deflected by magnetic field as they consist of no charge. 

The permissible level is 50 db. 

Infrared rays helps in reading an old written material. 

Centrifugal force separates fat from milk.

When brush is taken out, the water film is formed between the hairs and they contract due to surface tension.

The appearance of blue colour of sky is due to scattering of light which is not possible in absence of atmosphere.

The tanning and sun burning of human skin is due to the harmful ultraviolet radiation from the sun.

Red phosphorus is mostly used in the manufacture of safety matches.

Butter is an example of a colloidal dispersion of a liquid in a solid i.e., gel.

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

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 )

Water has the maximum density among these because chloroform, benzene and ice float on water.