Model Practice Test- 2 - UPSC MCQ

 Americium is a synthetic chemical element with symbol Am and atomic number 95. It is radioactive and a transuranic member of the actinide series, in the periodic table located under the lanthanide element europium, and thus by analogy was named after the Americas.

Milk contains a protein called casein. This protein gives milk its characteristic white colour. It is of high nutritional value because it contains all the essential amino acids required by man's body. The curd forms because of the chemical reaction between lactic acid bacteria and casein. When curd is added to milk, the lactic acid bacteria present in it cause coagulation of casein and thus, convert it into curd.

The same considerations apply to the even more terrible hydrogen bombs. Our sun and the other stars are really natural hydrogen bombs in a process of continuous explosion. This is not merely an analogy: it is an exact description of the nature of a star. In the central core of the sun hydrogen is continuously reacting, or burning, into helium; and this is the very same process which takes place in a hydrogen bomb. Thus all our usual energy resources on earth, since they are ultimately derived from solar energy, owe their origin to a naturally occurring hydrogen bomb. The whole vast expanse of the universe is populated with hydrogen bombs. Indeed. they are the most common and abut). dant things in all creation, and they are the source of all light and life in the universe. 
 

The correct optio s A.
Once initiated, the original material is rapidly converted into a gas at very high temperatures and pressures. This process is called “detonation” and it creates a shock front which advances at the speed of several thousand meters per second.

The comet's ice was the "glue" that held the comet dust and rocks together. Then, as the comet came closer to the Sun, the surface ice evaporated, leaving little or no "glue." The rocky and dusty structures would then be fragile and crumbly.

Gypsum is the common name of the mineral calcium sulphate dihydrate, which is mined in various places around the world and now is also being produced in a relatively pure form as a by-product of sulphur dioxide removal processes for power station exhaust gases. On heating, dehydration of the dihydrate occurs in two distinct stages. The fairly rapid loss of three quarters of the water of crystallization at about 130 °C gives the hemihydrate. Further and now complete dehydration occurs at higher temperatures to give anhydrite. 

Soaps are sodium or potassium salt of higher fatty acids like, stearic acid, oleic acid, palmitic acid etc. 
Soaps are obtained by the alkaline hydrolysis of oils and fats. Only glycerides of filtty acids gives soaps on alkaline hydrolysis. 

C is the correct option.All toxic waste need to be dealt with safely, not just radioactive waste. The radioactivity of nuclear waste naturally decays, and has a finite radiotoxic lifetime. Within a period of 1,000-10,000 years, the radioactivity of HLW decays to that of the originally mined ore.

Cyclohexane is a cycloalkane with the molecular formula C₆H₁₂. Cyclohexane is a colourless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products. Cyclohexane is mainly used for the industrial production of adipic acid and caprolactam, which are precursors to nylon. 

Fructose is a natural simple sugar found in fruits, honey, and vegetables.  In its pure form, fructose has been used as a sweetener since the mid 1850s and has advantages for certain groups, including people with diabetes and those trying to control their weight.  Of course, fructose has been consumed for centuries in foods we still eat.  It is known as a simple sugar because it is a single sweetening molecule.  Fructose is also known as a monosaccharide.

Atomic clock measures time very accurately because it is based on the vibration of atoms and vibration of atoms are not effected by the movement of earth or the sun.

Generally acid denotes a substance which tastes sour but in Chemistry, its meaning is not limited up to this concept only. Acids are sour in taste. Most substances that contain acid taste sour due to the presence of acid. Many fruits like lemons, limes, grape fruits and orange contain citric acid. This is what gives them a sour taste. Such fruits are also called citrus fruits. Unripe fruits like green apples, plums and currants contain malic acid. The pickle gets its sourness from vinegar or acetic acid. Sour milk contains lactic acid. Tartaric acid is present in big lime (Bhogate). 

Protein digestion begins when you first start chewing. There are two enzymes in your saliva called amylase and lipase. They mostly break down carbohydrates and fats.

Once a protein source reaches your stomach, hydrochloric acid and enzymes called proteases break it down into smaller chains of amino acids. Amino acids are joined together by peptides, which are broken by proteases.

A major advantage to using solar energy is that it is a renewable resource. We will have a steady, limitless supply of sunlight for another 5 billion years. In one hour, the Earth’s atmosphere receives enough sunlight to power the electricity needs of every human being on Earth for a year. 

‘Polythene’ is an abbreviation of the word Polyethylene, which is a polymer of ethylene, (molecular formula: CH₂=CH₂). It is a synthetic polymer, and hence it belongs to the substances we use to call Plastics.Polyethylene is a ‘Plastic’ because it is an artificial polymer and it is not a ‘Rubber’ because it is not elastic.

LSD (lysergic acid diethylamide), first synthesized in 1938, is an extremely potent hallucinogen. It is synthetically made from lysergic acid, which is found in ergot, a fungus that grows on rye and other grains. It is so potent its doses tend to be in the microgram range. It's effects, often called a "trip" can be stimulating, pleasurable, and mind-altering or it can lead to n unpleasant, sometimes terrifying experience called a "bad trip."

Aspirin, or acetylsalicylic acid (ASA), is commonly used as a pain reliever for minor aches and pains and to reduce fever. It is also an anti-inflammatory drug and can be used as a blood thinner.

Ozone decomposes easily to give and thus improves the percentage of oxygen at crowded places, such as cinema halls, tube railway, etc. Ozone is a germicide and helps in killing microbes and destroying the foul smell in the atmosphere by the bad-smelling object.

The correct option is D.
chemical etching is done with hydrochloric acid on a glass surface.

Cement is formed by burning of graphite and limestone in a hot kiln. Many other materials such as shells , chalk or marl combined with shale, clay, slate blast furnace slag , silica sand and iron ore are also used in manufacture of cement.

Lamination can be defined as a process in which a number of sheets are heat-pressed and glued together to form a permanent bond. In the case of plywood, slices of wood (veneers) are placed over one another and bonded together using hot-press machines and adhesives. So plywood itself can be thought of as being laminated plywood.

Brominated vegetable oil (BVO) is a complex mixture of plant-derived triglycerides that have been reacted to contain atoms of the element bromine bonded to the molecules. Brominated vegetable oilis used primarily to help emulsify citrus-flavored soft drinks, preventing them from separating during distribution.