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HIRANANDANIFOUNDATION SCHOOL,THANE Second Preliminary Assessment - January 2024 Subject- Physlcs Time: 2 hours Std: X Date:177 01/2024 M. Marks:80 Answers to this Puper must be written on the paper provided separately. Y'ou will not be allowed to write during the first 10 minutes. This time is to be spent in reading the question paper. The time given at the head of this Paper is the time allowed for writing the answers. This paper consists of 8printed pages. Section Ais compulsory. Attemptany four questions from Section B. The intended marks for questions or parts of questions are given in brackets l } SECTION A (Attempt all questions from this Section,) Question 1 Choose the correct answers to the questions from the given options. [15] (Do not copy the question, write the correct answers only.) and a vibrating () Refer to the diagram given below, Water in the test tube is slowly emptied out of the air height tuning fork is placed above the test tube. A loud sound is heard when the column is 17 cm. The next loud sound will be heard when the height of the air column is Sacond Resonance Fizst Resonance Alr Aur 512H S12Hz (a) 34 cm (b)25.5 cm (c) 51 cm (d) 68 cm corect connection for both the switch (ii) Which diagram from the following shows the and the fuse? switch ive wire ive i e fuse neutral wite (eutral wire SWIlh fuse Sw!ch fusc fiva wire Doutral wite B reulral re switch (i) ln which direction will the galvanometer deflect when a magnet kept ncar solenoid moves in the direction of arrowv shown in the diagram? (a) left (b) right (c) left and right (d) no deflection is observed (iv) Anucleus of element Xis (a) x (b) 8X represented asX. An isotope of element Xis () x (d) 28X (V) The refractive indices of four substances P, Q,R S are 1.77, 1.50, 2.42 and 1.31 respectively. When light travelling in air is incidentandobliquely on these substances, the angle of refraction will be the maximum in (a) P (b) Q (c) R (d) S (vi) Which of the following is not a characteristic of a parallel combination of resistors? (a) The equivalent resistance is more than the least resistor connected in the combination. (b) The potential difference across all resistors in combinations is of constant magnitude. (c) The current divides in the inverse ratio of resistances in combination. (d) IfI is the total current in circuit I3 resistors then, I = I1 + l2 + ls. andl+I2+ are the currents in individual (vii) At trafic signals, red light is used to stop the vehicles due the reason that it can be seen from adistance. The phenomenon involved is known as: (a) Reflection (b) Refraction (c) Scattering (d) Dispersion 2 (vii) Which of the following is not comect for a step-down transfomer? (a) number of turns in primary coil are more than the secondary coil. (b) the primary coil is thinner as conpared to the sccondary coil. (c) the primary coil is thicker aS compared to the secondary coil. (d) the primary coil is more heavily insulated as compared to the secondary coil. reaction is due to (IX)The energy released during nuclear fission and nuclear fusion (a)Chemical reaction. (b) The conversion of electrical energy into heat energy. (c) The conversion of gravitational potential energy into kinetic energy. (d) The conversion of mass into energy. centripctal force is (x) In case of' uniform circular motion, the work done by the (a) Equal to the displacement of the body. (b) Equal to the force applicd on the body. (c) zero. (d) change in momentum ofa body. (xi) Assertion: Convex lens is used to correct long sightedness. of light from Reason: A convex lens of suitable focal length converges the parallel beam retina, the distant object. This helps the eye lens to form a clear image on the (a) both assertion and reason are true. (b) both assertion and reason are false. (c) assertion is true but reason is false, (d) assertion is false but reason is true. (xii) Specific heat capacity of a substance is 1800 J kg c means: (a) substance X absorbs 1800Jheat for 1 C rise in temperature. (b) 1kg of substance X absorbs 1800 J heat for 1 C rise in temperature. (c) 1kg of substance X absorbs 1800J heat to inerease the temperature, 1C, (d) 1kg of substance X absorbs 1800 Jheat to cool down the substance by (xii) A lever for which mechanical advantage is always less than 1 has the: (a) fulerum between load and effort, (b) load between effort and fulerum. (c) effort between fulerum and loud. (d) load and effort acting at the same point. (xiv) Apendulum is oscillating freely in vacuum. Its bob has: (a) only kinetic energy. (b) maximum potential energy at it's mean positiou. (c)maximum kinetie energy at it's extreme position. (d) aconstant energy which is the sum of potential and kinetie energy. (XV)Assertion: Water is used asa coolant in automobile radiators and for fomentation" Reason: Water has low specific hcat capacity. (a) both assertion and reason are true. (b) both assertion and reason are false. (c) assertion is true but reason is false. (d) assertion is false but reason is true Question 2 ()(a) Specific latent heat of vaporization of a liquid is 2000 J kg-, How much heat encrgy required to completely evaporate 2kg of this liquid if the initial temperature is equal to its boiling point? (31 (b) A radioactive nucleus emits a gamma ray. Does the position of the daughter element change in the periodic table? Justify your answer. (c) Anucleus C is a -radioactive. What is the general name of the daughter nucleus with respect to C? (i1) The diagram given below shows a lever in use. [2] Effon (E) Load (L) (a) To which class lever does it belong? (b) If FA= 40 cm, AB = 60 cm, then find mechanical advantage of the lever. (i ) A circular disk is made of copper and steel. Weight of copper is 5 gand weight of steel (2] is 10 g. On which half (copper or steel) does the centre of gravity lie? Justify your answer. steel.oPPer (iv)A machine which is 75 % efficient, uses 12 J of energy in lifting up a 2 kg mass through 2] a certain height.This mass is then allowed to fall from the same height. What willbe it's velocity at the end ofit's fall? (v) (a) Draw displacement and time graph for a body executing free vibrations. (b) Under which condition a body execute free vibrations? (2] (vi)(a) Asubstance has infinite conductance at a very low temperature. What is such 12] substance called? (b) How does an increase in the temperature affect the specific resistance of a semiconductor? (vii) (a) A uniform circular motion is an accelerated motion.State whether the acceleration produced is unifom or variable? (b) Name the force responsible for acceleration of a moving body along a circular path. 4 Question 3 (0) Sudha finds out that the sharp image of the window pane of her (21 science laboratery 5 fommed at a distance of 1Scm from the lens a on screen. She now focuses a tree Visible to her outside the window without disturbing the lens. Identify the type of lens. What is the approximate focal length of the lens? () (a)Name the electric component which of current and can also be used as a protects the electric circuit in case of excess flow switch. (21 (0) Name the wire to which the electrical component mentioned in Q i-fa) is above connected in an electric cincuit. (m) The diagran given beloy shows the core of a transtommer and its input and output connection. Primary winding 21 Secondany wnding (a) Identify the transformer. (b)State whether the turn ratio of the transfornmer is, n=l or > l or<l (iv) How much heat energy is released when S g of water at 20C changes to ice at 0 C? [Specific heat capacity of water = 4.2 Jg C; Specific latent heat of fusion of ice = 336 Jg] 21 (v) (a) Write one point of difference between Nuclear fission and Radioactive decay. 21 (b) Rewrite and complete the following nuclear reaction by flling in the atomic nunber of Ba and mass number of Kr. + 14+Ba + Kr + 3 ~n + Energy SECTION B (Atempt any four questions,) Question 4 (i) The diagram below shows the ray OP travelling through an equilateral prism of a certain material. (a) Calculate the value of i2. if the angle of deviation is 43 . (b)Retractive index of diamond with respect to air 2.41. Calculate the speed of light in diumond. (31 (m) Equilateral prism ABC is made of glass which has the critical angle 48 Z DEC = 138 and Z EDB = 90 . 138 (a) Copy the diagram and Draw the path of incident ray on the side AB (which travels along DE.) till it emerges out of the prism. (b) Mark the measures of all the angles in the figure. (ii) Figure below shows the refraction and emergence of a ray of light glass slab of thickness D'cm. incident on a rectangular 14] Incident ray P Refracted ray Glass block D Cm M cmer 9en Direction of incident ray (a) Name and define 'XY' labelled in the diagram. (b) State the effect on XY when: (1) 2idecreases. (2) D increases. Question 5 (i) A concave lens has a focal length of 20 cm. At what distance from the lens a 5 cm tall be placed so that it forms an object image at a distance of 15 cm from the lens? Also calculate the size of the image formed. 3 (ii)(a) Scattering is absorption and re-emission of light in different direction. [3) What is the relation between intensity and (b) The diagram shows the incidence of a wavelength of a scattercd light? polychromatic light composed of red, yellow, blue and green on a prism. R+G+81Y X FRISM SCREEN (1) Name the colour of emergent rays labelled X' and Y'. (2) Which olour of (iii) (a) Write the following light emerging out of the prism deviates the least? Give reason. radiations in an ascending order with respect to their frequencies: [4) X- rays, microwaves, UV (ultra violet) rays and radio waves. (b) The wavelength of X-rays is 0.01 A.Calculate it's frequency. State the made,if any. assumption 6 Question 6 (i) Ablock and tackle system of pulleys has a velocity ratio 4. (a) Draw aneat, labelled diagram of the system indicating the points of application of load, effort and tension and their direction. (b) What will be it's V.R if the weight of the movable block is doubled? () 1he adjacent diagram shows a wheel of diameter 40 cm fixed on a wall capable of rotating around its centre O. If the wheel rotates in an anticlockwise direction, then: (3) P |100gf (a)Calculate the clockwise moment. (b) State whether X= 100gfor X< 100gf or X >100gf. in Qii-(b) (C) Give a reason to support your answer mentioned of 18 km hand (ji1) A car of mass 120 kg is moving at a speed of 54 kmh' in 5 s .Calculate: (a) the work done by the engine. above. it accelerate to attain a speed 14] (b) the power of the engine in H.P. Question 7 certain region in space. () A beam of a, Band y rays is travelling through a power. (a) Arrange them in ascending order ofionising the age of excavated material estimate to used is radiations three the (b) Which among (3| of archaeological importance? (c) What is background radiation? three 2, 3 Q and 6 2. How will youconnect the (i1) You have three resistors of values 2 Q? resistors so that the total resistance 4 (a) Drawa diagram for the arrangement. the diagram drawn. (b) Calculate the equivalent resistance to justify starts the of 4 vibrations per second. An observer (iii) (a) A pendulum has a frequency cliff after the from echo the hears pendulum and fires a gun simultaneously. He velocity of sound in air is 340 ms', find the 6 vibrations of the pendulum. If theobserver. distance between the cliff and the (b) The figure given below shows a circuit reads 0.5 A, 6.0 V 30 R Calculate: (1)value of unknown resistor 'R'. (2) power distributed in the 32 resistor. which when switched on, the ammeter [31 141 Question 8 3) () Acertain sound has a frequency of 256Hz anda wavclength of 1.3 m. (a) Calculate the speed with which the sound travels in air. (b) What difference would be felt by a listener between the above sound and another sound travelling at the same speed, but of wavelength 2.6 m? [3| (ii) An atomic nucleus 'X is composed of 84 protons and 128 neutrons. (a) The nucleus X` emits an alpha particle and is transformed into nucleus B. Represent the composition of nucleus B in the form of an cquation? (b) Write one safety measure while establishing a nuclear power plant. (i i) (a) 40g of ice at 0 C is used to bring down the temperature of certain mass of water 14] at 60 C to 10 C. Find the mass of water used. Given: Given Specific heat capacity of water =4.2 J g c Specific latent heat of ice =336 J g (b) How is the loss of heat due to radiation minimised in a calorimeter? Question 9 (i) Four amps of 200 W, 100 W, 80 Wand 60 W are connected to a power supply of 220 V.Calculate: (3| (a) total current consumed. (b) the cost of energy consumed if the lamps are lighted for 7 hours daily for 30 days. The cost of electricity is 6.50 per kWh. (ii) The diagram given below shows a magnet placed between two coils A and B. The magnet is moved along the axis towards coil B. Maguet N S (3] B (a) State the polarities induced at the ends Q and R of the coil due to the motion of the magnet. (b) Name the phenomenon due to which the current is induced in the coils. (c) Name the law which helps to find the polarities at the ends Q and R. ( i) The diagram given below shows a rectangular coil ABCD, suspended freely between the 14) poles of a permanent horseshoe magnet, such that the plane of the coil is parallel to the magnetic field. (a) What is the direction of current in the coil, when curent is passed through the coil? (b) In which direction the coil will begin to rotate when current is passed through the coil? (c) When will the couple acting on the coil be minimun? (d) Name the rule, which will help youto determine the direction of force acting on the coil.
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