8. Explain how the common Steelyard is graduated; and shew how its sensibility can be increased. 9. Demonstrate the Principle of Virtual Work for the lever. Apply this principle to solve the following problem: a lever without weight in the form of an arc of a cirele subtending an angle 2a at the centre, having two weights P and Q suspended from its extremities, rests with its convexity downwards on a horizontal plane; prove that in the position of equilibrium PQ makes with the horizon an angle tan -1 P P+Q tan a a). 12 10. Explain the meaning of limiting friction, and give the laws gov. 11 erning it. A uniform rod rests within a fixed vertical circle and subtends an angle 2a at the centre; its upper end is smooth, and its lower end rough, the coefficient of friction being tanλ: shew that the greatest angle which the rod can make with the horizon is 6, where N.B.-The two sections should be kept separate. Definite chemical changes should be represented by equations, SECTION I. 1. How would you obtain chlorine for experimental purposes? 14 What would you notice when you successively introduce into different jars of chlorine (1) a piece of phosphorus, (2) a lighted jet of hydrogen, (3) antimony powder, and (4) sulphuretted hydrogen solution? 2. A mixture of chlorine and oxygen and another of chlorine and hydrogen and an aqueous solution of chlorine, respectively, are exposed to the rays of the sun. Describe what will happen in each case. On what do the bleaching properties of chlorine depend? 3. Seventy-five grammes of a solution containing 21 per cent. of am- 12 monia are added to 134 grammes pure nitric acid. Find the weight of ammonium nitrate produced and of nitric acid remaining unsaturated. 4. How are the chlorides of phosphorus prepared and how are they severally acted on by water? What is the action of the higher chloride on sulphuric acid and alcohol? SECTION II, 5. You saturate two solutions of caustic potash with chlorine, one at a l low temperature and the other at about 70°C.; what changes will occur? How would you prove that the two solutions contain different salts and how would you separate the salts which are present in the warm solution ? 6. How would you prepare from the trioxide of arsenic a saturated 17 solution of sodium arsenite and how would you change a part of this solution into arsenate ? Give at least two different tests by which you may prove that the first solution contains arsenite and no arsenate, whilst the second contains arsenate and no arsenite. 7. What different compounds of antimony can you prepare, if you are 16 provided with antimony, its native sulphide, hydrochloric and nitric acids and caustic soda? What is in your opinion the best method of procedure in their preparation? THURSDAY, 7TH NOVEMBER. CHEMISTRY-PAPER II. N. B.-The two Sections should be kept separate. Definite chemical changes should be represented by equations. SECTION I. 1. What is the action of acids, alkalis and water on zinc ? How is 12 zinc oxide prepared? Describe the preparation of the chloride and sulphate and give their properties. 2. Describe in detail the methods you would use in the laboratory in 12 order to prepare the following substances in the pure state from metallic copper : Cupric oxide, cuprous oxide, cuprous chloride and cupric sulphate. 3. If you are given mercuric chloride how would you get calomel 14 from it? The vapour density of this compound is found to be about half of that demanded by the formula Hg,Cl. How do you account for this? 4. Given a solution of potassium permanganate. Explain how the fol- 12 owing substances can be obtained with its aid : Manganese dioxide, Manganous sulphate, Chlorine and Oxygen. SECTION II. 5. How would you prepare a specimen of pure, solid ammonium 13 carbonate from the ammoniacal gas-liquors ? 6. How would you prepare cuprous chloride, mercurous nitrate and 13 platinous chloride from the respective cupric, mercuric and platinic compounds, and how would you obtain solutions of these salts ? State what changes (if any) these solutions are liable to undergo in the course of time. 7. What is the effect of heat on zinc carbonate, mercuric iodide, lead 12 mitrate, stannous oxide, chromium trioxide and potassium permanganate ? 8. The percentage composition of a salt is as follows: Find its molecular formula and state exactly how you would proceed to prepare from it crystallised boric acid. (B: 0: Na=11: 16: 23.) 12 THURSDAY, 7TH NOVEMBER. 1. State Newton's second law of motion and prove the triangle of forces. 10 A weight of 100 gr. is suspended by a thread from a hook and pulled aside by another thread which is fixed to the middle of the first. Find the force required to pull it until it makes an angle of 30° with the vertical. 2. Describe the pyknometer and explain how the instrument may be 12 used to find the specific gravity of solids and liquids. What precautions are to be taken to get accurate results? The weight of a specific-gravity-bottle is 39'74 gr. when filled with water. A piece of metal weighing 8.5 gr., which was said to be gold, was introduced and the bottle filled with water. The weight was now 47.12 gr. Was the metal true gold? If not, find the weight of the bottle with the metal in case it was gold. (Specific gravity of gold = 19·5.) 3. Describe Bianchi's air-pump. In what regards is it superior to the 19 common air-pump? Give the reasons why it is impossible to produce a perfect vacuum by a common air-pump and explain the different appliances you know to produce at least a vacuum of 1 m. m. pressure. 4. Explain how in an organ-pipe stationary waves are produced. How 10 can you show experimentally the existence of nodes and loops in an organ-pipe? 5. How is the diatonic scale composed? Explain "major and minor 12 triad, tonic, dominant and subdominant." How do you find the interval between two notes ? Define "tone, semitone and comma" and find the number of vibrations of C sharp, F and B flat, the number of vibrations of C being 256 per second. (Do not take any regard to temperament in your calculation.) In 10 6. Define linear coefficient of expansion. How is it determined? what regard is Roy and Ramsden's method superior to that of Lavoisier and Laplace ? 7. Explain fully the following phenomena : Mousson succeeded in melting ice at 18°C. Bunsen kept spermaceti in the solid state at 51°C. though its melting point is 48°C. Helmholtz placed a bottle from which the air was expelled and which was partly filled with water in melting ice. The water in the bottle was found to freeze, whilst at the same time the ice outside the bottle was melting. 12 8. Explain according to the kinetic theory how cold is produced by 10 evaporation and show how this is applied in Carre's ice-machines. 9. Explain fully what is meant by "equivalent of heat." Find its 12 numerical value from the following data : 1. State the laws governing reflection and single refraction of light, 10 and show how the reflection and refraction of a plane wave, at the plane dividing surface between substances of different optical density, is explained by means of the undulatory theory. 2. Explain how a prism is adjusted for minimum deviation. Show 12 that the refractive index of the material of a prism for light of a certain wave length is n = sin · (4 + d) 2 sin where is the angle of the prism, and d the angle of minimum deviation for this particular kind of light. 3. What are the defects of the eye known as astigmatism and myopia? 10 How can each be corrected? In a myopic eye the greatest distance of distinct vision is found to be 0.5 meter, find the focal length and the power in diopters of the proper correcting lens. 4. A Nicol's prism is placed in the path of each of two beams of light, 12 which come from the same source, and fall on a screen, producing interference bands. One of the Nicol's is rotated; explain what is seen on the screen. 5. Show that in the case of a static charge the stored energy is half the 12 product of the quantity of electricity and the potential. Also that in the case of an electric current the energy delivered to any part of the circuit outside the generator is the product of the quantity flowing into the difference of potential between the ends. 6. How can a voltameter be used to determine the constant of a tangent 10 galvanometer? 7. How can the magnetic moment of a solenoid conveying a given 10 current be compared with that of a bar magnet? 8. Explain what takes place when the number of magnetic lines of 12 force through a closed electric circuit is increased or diminished. In what different ways may such alterations be made? 9. Describe the Gramme ring armature, and show how the electromotive 12 forces produced in the different coils combine together. MONDAY, 4TH NOVEMBER. GENERAL BIOLOGY. SECTION I. 1. What is a growing point.? Where is it situated in the stem and the 12 root? Name the histogenic cell layers found there, and mention the permanent tissues that are developed from them. 2. What is the nature of the food of plants? How is it absorbed from 13 the soil? By what channels is it transported to the assimilating and growing organs? 3. Describe the structure of the ovule of an angiosperm, and trace the 12 changes it undergoes during and after the process of fertilisation till the formation of a perfect seed. 4. Describe the structure, mode of reproduction and general life history 13 of Saccharomyces cerevisa. SECTION II. 5. Contrast the respiratory system of a Frog (including Tadpole), Dog- 19 fish, and Rabbit. 6. Describe the structure of blood, hyaline cartilage, and bone, and state to briefly what you know of the development of these tissues. 7. Describe the Amphioxus, and state briefly in what characters it resem- 15 bles and differs from higher Vertebrates. 3. Compare and describe the masticatory apparatus of a Cockroach and 15 an Astacus. Also state what you know of the antennæ of both. MANCHERJI KAVASJI KANGA, M.A., B.Sc., L.M. & S. B.Sc., Major C. H. L. MEYER, M.D., B.S., M.R.C.S., I. M.S. ... ... In Animal Physiology. |