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HUTCHINGS HIGH SCHOOL AND JUNIOR COLLEGE PRELIMINARY EXAMINATION : 2024 - 2025 PHYSICs CLASS- X DURATION : 2 HOURS Total number of printed sides :6 (Answer all questions) MAX. MARKS:80 Question 1 Choose the most appropriate answer from the given [15] options (i) Which of the following quantities does not affect the torque acting on a body? (a) Magnitude of force applied (b) Perpendicular distance of the line of action of the force form axis of rotation (c) Both (a) and (b) (d) Mass of the body (ii) A radiation R is focused by a proper device on a bulb of a thermometer. Mercury in the thermometer shows a rapid increase. The radiation R is: (a) ultraviolet (b) Infra red (c) X rays (ii) (d) Visible light Which of the following produces magnetic field in the form of comcentric circles? (a) Bar magnet (b) solenoid (c) Straight conductor (d) All of these (iv) Lenz's 1law is based on the law of conservation of : (a) Mass (b) Charge (c) Momentum (d) energy (v) An air column has a natural frequency of 320 Hz. A tuning fork of frequency 256 Hz is set into vibrations and held close to air column. Then air column vibrates with a frequency( in Hz) (a) 0 (b) 256 (c) 320 (d) 576 (vi) Assertion(A): The mechanical advantage of an ideal single movable pulley is independent of the weight of the pulley. Reason(R): An ideal single movable pulley can be used as a force multiplier. (a) Both A andR are true, and R is the correct for explanation (b) Both A andR are true, and R is NOT the correct explanationthe forA the A (c) A is true, but the R is false. (d) A is false, but the R is true. (vii) For an object placed 20 cm in front of a convex lens, the is at a distance of 20 cm behind the lens. The focal length of theimage convex lens is: (a) 10 cm (b) 15 cm (c) 20 cm (d) 40 cm 1 (viii) A solar cell converts solar energy into: (a) Heat energy (b) Mechanical energy (c) Chemical energy (ix) (d) Electrical energy The unit of clectrical power is (a) Volt ampere (b) Kilowatt hour (c) Ohm meter (x) (d) Ohm ampere For a given force and given angle between them is(in displacement work done is minimum wher degrees) (a) 0 (b) 60 (c) 90 (d) (xi) 180 According to the old convention the colour (a) Black of the live wire is: (b) Green (c) Yellow (d) Red (xii) Assertion: EMF(E) of a cell is greater than or equal to the Potential Difference(V) Terminal Reason: E=V+Ir (a) Both A and R are true, is the correct (b) Both A and R are true, andR explanation for the A and R is NOT the correct the A explanation for (c) A is true, but the R is false. (xii) (d) A is false, but the R is true. Amount of heat required to raise the celcius is its: (a) (xiv) temperature of body by one degree Latent heat of fusion (b) Specific heat capacity (c) Thermal capacity (d) Latent heat of vaporisation During the process of melting temperature of a change because (a) No heat is absorbed by the (b) Heat absorbed is utilised in substance changing potential energy of molecules (xv) (c) Heat absorbed is utilised in (d) None of the above Which of the following particles the highest speed? substance does not changing kinetic energy of molecules emitted during radioactive emission has (a) alpha (b) beta (c) gamma (d) All have same speed Question 2 (i) Complete the following by choosing the correct answers from the bracket: (a) In uniform circular motion, the work done by the centripetal force is always (zero/positive (b) If a light body A of mass m and a /negative) heavy body B of mass M have the same kinetic energy K then will have more (c) The momentum. mechanical advarntage of 2 (light/heavy) body (class I/ class II/ class |6] II) is greater than 1 (d) Alensalways in placed has (e) Current gets divided in (water/air) lesser focal length. (0 (series/parallel) combination of resistors. Daughter nucleus has (greater/ lesser) mass number than parent nucleus. (i) Why earth pin in a plug is made thicker and longer? (i) The diagram given below shows a ski jump. Askier weighing 60 kgi stands at A at the top of ski jump. He moves from A to B and takes oft for his jump at B. If 75% of potential energy lost from Ato B becomes kineticenergy, then find his speed at B.(g-10 ms) A 75m B Sm Question 3 Refractive index of a liquid with respect to air is V2. Find the critical (2] angle for the liquid - air pair. (ii) Mention any four properties of alpha particles. (2] (iii) Calculate the heat required to raise the temperature of 200 g of (2] water from 40 0C to 50 0C. (specific heat capacity of water = 4.2 x 103 Jkg1 0C-1) (iv) In a nuclear fission reaction energy released is found to 1395.5 MeV. (2] Find mass defect of the reaction. (v) What is magnifying power of a convex lens of focal length 5 cm if final image is formed at least distance of distinct vision?(D=25 cm) (vi) The natural frequency of an air in a pipe fixed at one end, of (2] length l7 cm is 500 Hz. At whatcolumn of air column, a tuning fork length of frequency 250 Hz with resonate with it? (vii) (a) Name the physical quantity by using the formula U/h, [3) where U is the potential energy obtained and h is the height. (b)Two persons do the same amount of work in 20 s and 40 s respectively. What is the ratio of the power used by first person to second person? Question 4 Section -B (Attempt any four questions from this section) (a) A radioactive nucleus X emits an alpha particle followed by two beta particles to form nucleus Y. 1) What is the general name of the elements X and Y? 2) With respect to the element X, where would you position the element Y in the periodic table? (b) If the atomic number of Y is 82 then what is the atomic number of X? (ii (a) Name the invisible radiation which is studied using quartz prism. (b) State one use of these radiations. (c) A mixture of red, blue and green is passed through a convex lens. State whether the ray will pass light through a single point or different pointson the principal axis after refraction. 3 (3] [3| (2) [2] (i) a) Draw system ofthree pulleys with correct direction of effort (b) If the of the system is 90% how much effort would be tequired toefficiency lift a load of 270 kgf using this system of applied. pulleys. Question 5 (1 4| The diagram given below shows an Copy the diagram and draw suitableobject O and its image . rays to locate the lens and its focus. [3| (11) Abody of mass m is dropped from a height H". Prove that at any point during its vertical (3) fall, its total mechanical energy constant and is equal tofree mgH. (Assume that there is no air remains resistance) (11) The diagram show three different modes of vibrations P, Q and R of (4) the same string. (a) which vibration will (b) The sound of which produce a louder sound? And why? (c) State the ratio of string will have maximum shrillness/ wavelengths of P and R. Question 6 {i) (i) (a) When sunlight passes through water droplets in the atmosphere it gets dispersed into its constituent colours forminga rainbow. A similar phenomenon is observed when white light passes through a prism. (1) Which colour will show minimum angle of deviation? (2) Instead of sunlight a blue coloured ray is passed through a glass prism. What will be the colour of emergent ray? (b) When an illuminated object is held in front of a thick plane glass mirror, several images are seen of which second image is brightest. Why? (a) State Faraday's law of electromagnetic induction. (b) Name any one device which works on law of electromagnetic (3] (3 induction. (c) Which law is used to find the direction of induced current? (iii) Consider the circuit diagram below to answer the questions that follow: 62 a) Calculate the resistance of the circuit when the key K is open. b) Calculate the resistance of the circuit when the key Kis 4 (4) closed. c What is the reading in the ammeter A? d) What is potential difference across 6 ohm resistor? Question7 3| (a) How does the internal resistance of a cell depend on: () 1) temperature of the cell 2) Concentration of the electrolyte (b) Define specific resistance of a conductor. [3 (i) The diagram below shows the path of light passing through a right angled prism of critical angle 420. (a) Find angle Cof the prism. (b) Complete the path of the ray as it cmerges out of the prism. 60 B (a) Draw a neat labelled diagram to show the refraction of a (ii) 4| monochromatic light by an equilateral glass prism. Mark and label all the important angles. (b) State any two factors on which angle of deviation depends. Question 8 3] (a) Name the wave used in SONAR. () (b) Aman fires a gun and hears its echo after 5 s. The man then moves 340 m towards the hill and fires his gun again. This time he hears the echo after 3 s. Calculate the speed of sound. (3] (a) An object is dropped in a swimming pool appears to be at a depth of 2.7 m. The refractive index of water with respect to air is 4/3. What is the shift produced by water? (b) How is the shift affected by thickness of the medium? (iii) The diagram below shows a coil connected to a centre zero galvanometer G. (41 The galvanometer shows deflection to the right when the N-pole of a powerful magnet is moved to the right as shown. N (a) Explain vhy the deflection oceurs in the galvanometer. (b) Does the direction of current in the coil appear clockwise or anticlockwise when viewed from end A? (c) State the observation in G when the coil is moved away from N. (d) State the observation in G when, both coil and the magnet, are moved to the right at the same speed. Question 9 (i) A uniform meter scale is in equilibrium as shown in the diagram. 5 em 30 cm 100 om O cm 40 f (a) Calculate the weight of the meter scale. (b) If 40 gf weight is shifted to 10 cm mark where can the scale be balanced? 5 3 (i) temperature(T) with heat of variation show to graph (a) Drawa of water over a range of supplied (0) to given quantity 110 C. [3) temperature from -10 C to (b) Define latent heat of fusion. having their mass in the (11) (a) Two blocks A and B of different metals temperature rises by ratio 2:1 are given same amount of heat. Their same amount. Compare their specific heat capacities. 960 JK-1. Find (b)A piece of iron of mass 2 kg has a heat capacity of heat energy needed to warm it by 20 C. 4|
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