Q307. Assertion (A): Large cold storage plants use ammonia as refrigerant while domestic refrigerators use chlorofluoro- carbons. Reason (R): Ammonia can be liquefied at ambient temperature and low pressure.

Assertion (A): The main constituent of the liquefied petroleum gas is methane. Reason (R): Methane can be used directly for burning in homes and factories where

Assertion(A): Synthetic detergents can lather well in hard water. Reason (R): Synthetic detergents form soluble calcium and magnesium salts with hard water.

Assertion (A): To dilute sulphuric acid, acid is added to water and not water to acid. Reason (R): Specific heat of water is quite large.

Assertion (A): With the increase of temperature, the viscosity of glycerine increases. Reason (R): Rise of temperature increases kinetic energy of molecules. Co

Assertion (A): Sodium metal is stored under kerosene. Reason (R): Metallic sodium melts when exposed to air. (a) Both A and R are true and R is the correct expl

Assertion (A): The boiling point of water decreases as the altitude increases. Reason (R): The atmospheric pressure increases with altitude. Codes: (a) Both A a

Assertion (A) : Anticyclonic conditions are formed in the winter season when atmospheric pressure is high and air temperatures are low. Reason (R) : Winter rain

Given below: Assertion (A): In the periodic table of chemical elements, electron affinity is always found to increase from top to bottom in a group Reason (R):

Assertion (A): Formic acid is a stronger acid than acetic acid. Reason (R): Formic acid is an organic acid. (a) Both A and R are true and R is the correct expla

Assertion (A): Phenyl is used as a household germicide. Reason (R): Phenyl is phenol derivative and phenol is an effective germicide. (a) Both A and R are true

Assertion (A): A jet aircraft moving at Mach Number equal to 1 travels faster at an altitude of 15 km than while moving at Mach Number equal to 1 near the sea l

Assertion (A): A jet aircraft moving at Mach Number equal to 1 travels faster at an altitude of 15 km than while moving at Mach Number equal to 1 near the sea l

Assertion (A): Unsaturated fats are more reactive compared with the saturated fats. Reason (R): Unsaturated fats have only single bonds in their structure.

Assertion (A): Coal-based thermal power stations contribute to acid-rain. Reason (R): Oxides of carbon are emitted when coal burns.

Assertion (A) : The amount of moisture in the atmosphere is related to latitude. Reason (R) : The capacity to hold moisture in the form of water vapour is relat

Assertion (A): The temperature of a metal wire rises when an electric current is passed through it. Reason (R): Collision of metal atoms with each other release

Assertion (A) : In Australia, cattle rearing is done more for meat than for milk. Reason (R) : Australians are traditionally non vegetarians

Assertion (A) : India does not export natural rubber. Reason (R) : About 97% of India’s demand for natural rubber is met from domestic production.

Assertion (A): A piece of copper and a piece of glass are heated to the same temperature. When touched, thereafter, the copper piece appears hotter than the gla

Assertion (A) : Existence of human life on Venus is highly improbable. Reason (R): Venus has extremely high level of carbon dioxide in its atmosphere.

Assertion (A) : 60° - 65° latitudes in both the hemispheres have a low pressure belt instead of high pressure. Reason (R) : The low pressure areas are permanent

Assertion (A): In human body, liver has important role in fat digestion. Reason (R): Liver produces two important fat-digesting enzymes.

Assertion (A): Drinking of whisky increases the frequency of urination. Reason (R): Alcohol intake speeds up the secretion of vasopressin in the body.

Assertion (A): An iron ball floats on mercury but gets immersed in water. Reason (R): The specific gravity of iron is more than that of mercury. Codes:

Assertion (A): Dolly was the first cloned mammal. Reason (R): Dolly was produced by in vitro fertilization.

Assertion (A): A man standing on a completely frictionless surface can propel himself by whistling. Reason (R): If no external force acts on a system, its momen

Assertion (A): Amoeba reproduces by fission. Reason (R): All unicellular organisms reproduce by asexual methods.

Assertion (A): In our houses, the current in the A.C. electricity line changes direction 60 times per second. Reason (R): The frequency of alternating voltage s

Assertion (A): Human diet should compulsorily contains glycine, serine and tyrosine. Reason (R): Essential amino acids can not be synthesized in the human body.

Assertion (A): Transformer is useful for stepping up or stepping down voltages. Reason (R): Transformer is a device used in D.C. circuits. In the context of the

Hydrogen fuel cell vehicles produce one of the following as “exhaust”:

In a dry cell (battery), which of the following are used as electrolytes?

Which one of the following types of glass can cut off ultraviolet rays?

With reference to ionic compounds, consider the following statements: 1. Ionic compounds are insoluble in alcohol. 2. Ionic compounds in the solid sta

Regarding the atom of a chemical element , the magnetic quantum number refers to:

Which one of the following statements is correct?

In an atom, the order of filling up of the orbitals is governed by:

A radioactive substance has a half-life of four months. Three-fourth of the substance would decay in: