Q224. Assertion (A): With the increase of temperature, the viscosity of glycerine increases. Reason (R): Rise of temperature increases kinetic energy of molecules. Codes:

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): 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): 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): 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): 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): The weight of a body decreases with the increase of altitude on earth. Reason (R): The earth is not a perfect sphere. Codes:

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): Large cold storage plants use ammonia as refrigerant while domestic refrigerators use chlorofluoro- carbons. Reason (R): Ammonia can be liquefied

Assertion (A): Cellulose is used in making shatter-proof glass. Reason (R): Polysaccharides are not soluble in water. Codes:

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): 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): 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): A stick is dipped in water in a slanting position. If observed sideways, the stick appears short and bent at the surface of water. Reason (R): A

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

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): 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

Assertion (A): In a motion picture, usually 24 frames are projected every second over the whole length of the film. Reason (R): An image formed on the retina of

Assertion (A): Small glass beads fixed on traffic signals glow brightly when light falls upon them. Reason (R): Light is totally reflected when the angle of inc

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): Radio waves bend in a magnetic field. Reason (R): Radio waves are electromagnetic in nature.

Assertion (A): Radio waves bend in a magnetic field. Reason (R): Radio waves are electromagnetic in nature.

Assertion (A): To orbit around the Sun the planet Mars takes lesser time than the time taken by the earth. Reason (R): The diameter of the planet Mars is less t

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

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

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) : The surface winds spiral inwards upon the centre of the cyclone. Reason (R) : Air descends in the centre of the cyclone.

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

Four wires of the same material and of dimensions as under are stretched by a load of the same magnitude separately. Which one of them will be elongat

Three identical vessels A, B and C are filled with water, mercury and kerosene respectively up to an equal height. The three vessels are provided with

What is the approximate mean velocity with which the earth moves round the sun in its orbit?

Which one of the following is the correct sequence of the given substances in the decreasing order of their densities?

A car is running on a road at a uniform speed of 60 km/h. The net resultant force on the car is:

A spherical body moves with a uniform angular velocity (ω) around a circular path of radius r. Which one of the following statements is correct?

A weightless rubber balloon is filled with 200 cc of water. Its weight in water is equal to:

Consider the following statements: A 4-wheel vehicle moving in a sharp circular path at high speed will: 1. Overturn about its outer wheels 2. Overtur