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Don Bosco Academy Pre-board Examination 2023-24 Total Marks: 80 Time: 2 hrs. Class-X Sub: Physics SECTION A Choose the correct answers to the questlons from the glven options (Do not copy the question, write the correct answers only) 0Essential characteristics of equilibrlum is zero (a) momentum is cqualto zero (b) acceleration is equal to zero is (d)velocity equal to (c) K.E is equal to zero The quantity remains unchanged, when a sound that phylcal () 15 1s IA 1 LS QUESTION1. we ppes from one tf the angle of incidence is iand angle of refraction r, then M A index nz. TE R medium to another is (c) wave length (d) frequency (b)speed (a) Amplitude a is (H)fthe speed of moving partide tripled, then the ratio of its kinetik energy to Its momentum will be (d) 4:1 (b) 3:1 (a) 2:1 c) 9:1 a n, a to of refractive medium ray of light travels from medium of refractive index (iv)A | equal to (a) n (b) n (c) n1 n, sinl sin r (d 4_ (v).Which of the following colours has more lateral displacement ? (c) green -(d) violet (b) blue (a) red waves (vi).The correct descending order of the electromagnetic according to their 2 wavelength is (a) UV-rays, y- rays, microwaves, infrared rays (b) Infrared rays, microwaves, UV-rays, y- rays (c) y-rays, UV-rays, infrared rays, microwaves d) Microwaves, infrared rays, UV-rays, Y-rays is @ IC SE _2 0 at which entire weight of the body can be supposed to be concentrated (c) centre of gravity (d) central point (b) centroid (a) end point converts (vii).Solar cell (a) Heat energy to mechanical energY (b) Electrical energy to light energy (c) Chemical energy to heat energy (d) Solar energy to electrical energy (vii). The point (x).A ray of light incident at an angle of 48 on a prism of refracting angle 60, suffers minimum deviation. The angle of minimum deviaion would be se) 36 (d) 480 (b) 240 (a) 120 a is (x).What is the magnification of the image when lens of focal length 10 cm and cm ? object distance from the lens is 15 (b) (c) 4 1 internalresistance 12 2. The potential differential across its terminals when it is supplying a current of 50 mA is (xi).A 9V battery has V (c) 9.06 V (d)9.6 V is most in The liquids for specific suitable of the folowing radiators car? heat capacity of the liquids are given (b) 8.4 (a) 8.94 V (xi). Which (a)4Jg-K- (b) 2.1 Jg-'K (b) 1500J Kg'Kd)2100) Kg-K (xii).The chain reaction is controlled by absorbing some of the neutrons emitted in the fission process by neans of: (c) sodium liquid metal(d) cadmium (a) Graphite (b) heavy water Contd to page - 2 @ICSE_2024_MATERIALS Page (xiv).Fuse is an alloy of (a) lead and copper - 2 copper and tin Lc) lead and tin (d) bronze and tin It emits a beta particle and forms (*V).A radioactive nucleus is represented by a different nucleus of element Y. Which of the following represents this new nucleus? Y (a) Y (c) (b) 228y (d)y QUESTION 2 (a) iWhat is the necessary condition for a conductor to obey Ohm's law ? ii. Tworesistors of resistance 72 and 50 are first connected in series and then in parallel. Find the ratio of the effective resistance in first and second cases 3 (b).Name two devices which are the applications of electromagnetic induction 2 (c).i.What is the principle of method of mixture? i.Name the law on which the principle calorimetry of is based 2 (d).A lens can not form an image on the screen. i.Name the lens ii.Name the nature of the image 2 (e).i.An element X changes to another element Y with the emission of particle, Write down the equation showing changes in the nucleus. Take the proton number and mass number of X as Z and A. ii.Name the technique used to estimate the age of excavated material of archeological importance. Also name the isotopes that forms the basis of this technique. (b) TE R IA LS 2X. M A - State the purpose for which the following rules are used i. Right hand thumb ii. Fleming's right hand rule rule (g). Calculate the equivalent resistance between A and B 252 n Sn _2 QUESTION 3 0 6 2 2 30 2 4_ (0). (a). Calculate the heat absorbed by 200g solid ice 0 C Specific heat capacity of ice and water are to SE change to water at 60 C. The respectively 2100 J kgK-'and 4200 JkgK-. Specific latent heat of ice is 336000 J kg-1. 2 (b). Redraw and complete the path of the ray AB till it emerges out of the prism of Critical angle 42 . AB is the incident ray B. at @ IC 2 ((c)}A body is acted up on by a force and it moves. State two conditions when the work done is zero ((d).JWhen we open a door, the rotation of the door is produced by a couple consisting of two forces. What are the two forces and where do they act? (e). Give two examples of class I lever i. act as a force multiplier ii. act as a speed multiplier 2 2 2 @ICSE_2024_MATERIALS Page SECTION B 3 (attempt any 4 questions from this section ) QUESTION 4. (a).i.A uniform circular motion is an accelerated motion, whether the acceleration is uniform or not ?. Why ? i. Aplanet moves around the sun in an elliptical path.Where does it get the 1 LS energy ?. (b).i.You are given 3 pulleys, how willyou arrange these pulleys in block and tackle system. (draw a neat diagram showing all necessary marking) 2 Calculate the M.Aof this pulley system if its efficiency is 80% If (c). Orange light of wavelength 6600 A travelling in air gets refracted in water. the Speed of light in air is 3 x 10m-'and refractive index of water is /, find of light (i).the frequency of light in air. (ii) speed of light in water.(ii) wave length water 4 R in 3 IA ii. ( i i).Value of R ( ). Current in R 3 M A (a).From the given diagram, calculate (i). The total resistance of the circuit TE QUESTION 5. 0.4 A 4_ 20 R _2 0 2 a (b). A lens forms an inverted image of size same as that of the object. Draw diagram for the formation of this image. By calculation find the focal length of the lens if the distance between the object and image is 120 cm (c).i. A burning glass when held in sun light to focus on a piece paper, the paper catches ? fire. Which radiation of sun light is responsible for this phenomenon ? ii. Which radiation can produce vitamin D in food of plants and animals iii. Which particle or radiation can cause immense biological damage ? iv. Which particle or radiation has maximum ionising power ? QUESTION 6 @ IC SE (a).i. Drawa labelled diagram of a step up transformer. ii. Why do we use the wire in primary coil more thicker than secondary coil ? ii. Why can't we use a direct current (d.c) source instead of an alternating current (a.c) in a transformer? 3 (b). i.What are radio isotopes ? i. Name one radio isotope used in medical field and its use. Name one radio isotope used in industrial purpose and its use. metal piece of mass 20 gis at a temperature of 100 C. It is dropped in a calorimeter of mass 50 g and specific heat capacity 0.42 J g-K-, containing g 50 of water at 20 C. The resulting temperature of water is 22 C. Calculate the specific heat capacity of the metal (specific heat capacity of wateris 4.2 J gK-) iii. 3 (c). A QUESTION 7. (a). When a vehicle is moving at particular speed a rattling sound is heard some time. i. Name the reason for this condition. ii. How can we stop this rattling sound iii. Why is it dangerous to the vehicle ? 3 contd to page -4 a @ICSE_2024_MATERIALS Page -4 (b).1.Establish the relatlonship between momcntum and kinctic energy i. Why does It become colder after a hall storm Rewrite and complete the following nuclear reactlon by filling in the atomic number and mass number of Ba and Kr + n Ba + "Kr + 3n + EnergY 2 i.The diagram given below shows a dual control switch connccted to a bulb. (a). Copy the diagram and complete it so that the bulb is switched ON. (b). Out of A and B mention live bulb M A TE L QUESTION 2 R wire and neutral wire &. 4_ (a) The diagram shows different modes of vibration 3 @ IC SE _2 0 2 of string of length "" i.Which vibration is of largest amplitude ? ii. Which vibration is of least frequency iii. What is the ratio wave of length of figure B and A K (b). A simple pendulum moves to and fro motion. The mass of the bob is 200 g. At a certain time the bob reaches at its extreme position, there by the bob is at a height of 5 m from the ground. i.What is the potential energy at the extreme position ? ii.What is the total mechanical energy between its mean position andthis extreme position? iii.what is the speed of the bob at the mean position ? ( take g=10 ms-2) c). The diagram shows aspiral coil wound on a hollow cardboard tube AB. A magnetic compass is placed close to it. Current is switched on by closing the key. i.What will be the polarity at the ends A andB ii.Name the law or rule used to determine the polarity fii.How willthe compass needle be affected ? iv.Suggest one way to increase the strength of the magnetic field. Contd to page -5 @ICSE_2024_MATERIALS LS U 1 IA (C).1. 2 3 Page -5 Compau Key Rheostat 4 IA Cell LS w QUESTION 9. TE R ((a).One end of a lever of length 50 cm is placed on knife edge(F). On the other end a Weight() of 0.5N is suspended. An effort (E) is applied on the lever to make it in equilibrium, at distance of 10 cm from the fulcrum. i.Draw a diagram of this arrangement i.Calculate the value of effort i i.Calculate its M.A @ IC SE _2 0 2 4_ M A (b).i.Write down two condition for total internal reflection of light i. Give an application of total internal reflection, used to transmit a light signal over a long distance without any loss of energy (c).A person standing in front of a cliff fires a gun and hears its echo after 3 seconds. If The speed of sound in air is 340 m/s i.Calculate the distance of the person from the cliff iiAfter moving certain distance towards the cliff, he fires the gun again and hears the sound after 1.5 seconds. Calculate the distance moved @ICSE_2024_MATERIALS 3 3
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