राज्यसेवा पूर्व परीक्षा २०१७ - Paper 2

Read the following passage and answer the questions from 21 to 25 :
Sound waves are formed due to vibrations of particles and propagate in a material medium in the form of longitudinal waves. The sound waves of frequency less than 20 Hz are called infrasonic waves. The human ear can hear the sound waves between frequency range 20 Hz to 20000 kHz. This is the audible range. The sound waves of frequency greater than the audible range are audible to certain animals such as cats, dogs, bats, etc. These are the ultrasonic waves. While flying, a bat produces ultrasonic waves. These waves strike obstacles in their path and are reflected. The bat can use echoes to detect the obstacles and hence avoid collisions with them. Thus a bat can find its way even is the dark.
Ultrasonic waves are produced by piezoelectric oscillators and magnetostriction oscillator method and detected by Kundt's tube, Quartz crystal and Thermal detector methods.
The waves having more frequency, possess more energy. Hence ultrasonic waves possess high energy. Like sound waves, ultrasonic waves also get reflected, refracted and absorbed. Their velocity increases with frequency.
Ultrasonic waves are used in many industrial, scientific and medical sciences. Sound navigation and ranging (SONAR) is the instrument which can produce, transmit and receive ultrasonic waves. This technique is used to determine the distance and location of underwater objects such as submarines, icebergs, etc. using ultrasonic waves. It can be used to determine the depth of the sea. For this a transmitter and a detector are installed in a ship. Ultrasonic waves are also used for ship to ship communication, welding plastic surfaces, to kill bacteria in liquids like milk to preserve them, in echocardiography, for imaging internal organs of the human body, in industry to clean parts of machines, to detect cracks and flaws in metal blocks.

Read the following passage and answer the questions from 26 to 30 :
The subject Plant Breeding, although developed in recent times on modern scientific lines after Mendel's discoveries, was known in early times to Egyptians and Assyrians. Later during 18th and 19th centuries several artificial crossings were made by many workers and interesting results obtained in the form of new varieties. But it was Mendel who first laid down the foundations of plant breeding on scientific basis and formulated the laws of inheritance of characters.
Hybridisation between two varieties of a species brings about a combination of desirable characteristics. A plant breeder specializes in crossing plants with the desirable character. Thomas Fairchild (1717) was the first person to obtain a successful hybrid by crossing Sweet William and Carnation. The knowledge of Mendel's laws has made the job of a plant breeder scientific, reliable and predictable. In bisexual plants the anthers of stamens of the female parents have to be removed (emasculation) in order to prevent self-pollination. Emasculation is not required in unisexual flowers and in the self-sterile bisexual female parents. Male sterility has been reported in Maize, Wheat, Sorghum, Barley, Cucumbers, Tomatos, Onion and Sunflowers.
Sterile males are of great help in raising hybrids of desirable characters. Stigmas of the carpels are enclosed within polyethylene bags since the early stage to prevent pollination by the pollen grains of unwanted plants. The bags are put back in place after dusting the stigmas with the pollen grains of desirable plants. This process is called bagging.
Hybrids : The hybrids are usually interspecific i.e. intervarietal. Interspecific and intergeneric hybrids are not possible. A rare example of interspecific hybrids is the Mule in animals and the Triticale is an intergenetic hybrids between Wheat (Triticum) and Rye (Secale). Such hybrids are bound to be sterile due to lack of homologous chromosomes. Generally, a hybrid may be heterozygous for only one gene or for a number of genes.
The breeding of hybrid corn is a very significant example of hybridization. It is obtained by crossing two inbreed or homozygous lines of maize. The inbreed
lines are true breeding and highly uniform. कच्या कामासाठी जागा । SPACE FOR ROUGH WORK
Hybrid vigour or Heterosis: The hybrids often exhibit hybrid vigour which is defined as the increased vigour (superiority) of the hybrid over either parent in one or more traits e.g. in growth, yield, disease resistance, etc. Maize plants exhibit a very high degree of hybrid vigour (25% higher yield). Other plants showing hybrid vigour are Sorghum, Rice, Bajra, Sugarbeet, Petunia, Cabbage, Cucumber, etc. The plants which are self-pollinating types lose heterosis by inbreeding and therefore, pure parental lines are crossed every year to obtain seeds with high degree of heterosis.
On the other hand, hybrid vigour is not füst and persists if the desirable hybrid once obtained is subjected to vegetative propagation e.g. Mango, Apple, Guava, Dahlia, Chrysanthemurm, Rose, etc.

Read the following passage and answer the questions from 31 to 35 :
          During the interactions with a group of standard VI students, Dr. Sarvesh demonstrated various experiments involving physical changes viz. Vapourisation/Evaporation (liquid to gas), Melting (solid to liquid), Sublimation (solid to gas) and Chemical changes viz. Neutralization (reaction between acid and alkali), Precipitation (reaction between ammonium chloride/potassium chloride and silver nitrate).
          This group enjoyed the session and demanded little more information regarding detection of cations and anions in the given solution. With this demand, Dr. Sarvesh designed three experiments (one by observing the changes in the colours of the test papers and another, just observing the change) to detect the presence of ammonium radical in the given salts.
           Dr. Sarvesh dissolved a small amount (approximately 0-100 g) of each, solid ammonium chloride and solid potassium chloride separately in 2:0 cm of de-ionised water, in two different test tubes labeled '1' and '2' respectively. Two drops of each of the above solutions were separately taken in three different dry test tubes forming two different sets; one set kept on the extreme left and another on the extreme right. The three test tubes, in each of the two sets, were gently heated on adding six drops of 2 N sodium hydroxide (alkali) to each and the evolved gases were carefully brought in contact, separately, with a moist red litmus paper, a moist turmeric paper and a glass rod dipped in dilute hydrochloric acid.
            Above the test tubes on the left hand side, in the first case, the paper turned blue (this was exactly opposite to acidic gases which turn moist blue litmus red), in the second case the paper turned brown and in the last case dense white fumes of ammonium chloride were observed. No such changes were observed in the colours of both the papers nor dense white fumes above the test tube on the right. Dr. Sarvesh explained that during the reactions between the reagents gaseous ammonia is liberated which is alkaline in nature and inferred that the solution in the left hand side test tubes contains ammonium radical while that in the right hand side test tube does not.
            Dr. Sarvesh then asked students to perform the test. In the first experiment, Ms. Riya, in addition to the earlier observations, found red litmus turning blue for the test tube on the right while Mr. Ravi, did not get the desired colour change of the turmeric paper on the left hand side test tube. Dr. Sarvesh explained to the students the proper way to perform the tests. Following the instructions from Dr. Sarvesh, when the students correctly performed the tests, they got the desired results.

Read the following passage and answer the questions from 36 to 40 :
Robert Frost once famously defined a liberal as someone who could not take his own side in an argument. But contemporary constructions paint an opposite picture: Liberals are seen as self-satisfied ideologues with no stomach for a diversity of ideas. Exposing the political hypocrisy of liberals has become a rhetorical gambit to delegitimise the idea of liberalism itself. Alas, it has to be said that those who use this gambit have much ammunition to deploy. But there are also other sources of concern. Nicholas Kristof in a widely discussed New York Times column, argued that the hiring practices of American universities were biased against conservatives. Liberal institutions, rather than becoming shelters for diverse ideas and genuine contestation, were turning into monoliths of political correctness. Liberals were supposed to be able to think out of their skins; now they imprison themselves in boxes. Similar charges have been voiced in India, most recently by Gurcharan Das.
These charges are often political gambits. The charge that liberals exclude and ostracise conservatives comes in many forms. There is one version of this charge that liberals do not have to be defensive about. A conservative presumption in favour of an old order is quite often associated with hierarchy: this usually has the odour of sexism, racism, homophobia, casteism, and hostility to minorities. Sometimes liberals can promote a kind of faux sanitisation of the intellectual environment in ways that close off debate. But the idea that institutional spaces should not legitimise sexism, racism, casteism, and xenophobia is one that every decent society ought to promote.
There are conservative articulations that can, subtly or unsubtly, target specific groups. They make people uncomfortable in ways that have nothing to do with intellectual argument. Liberals are entirely right to be suspicious of these positions. To not be suspicious would be to abdicate a commitment to human dignity itself.