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EuroSchool Dlscover Yourself Preliminary Exam-1, 2024-25 PHYSICS Time allowed: Two hour GRADE: X Max. Marks: 80 Answers to this Paper must be written on the paper provided separately. You will not be allowed to write during first 15 minutes. This time is to be spent in reading the The time given at the head of this question paper. Paper is the time allowed for writing the answers. Section A is compulsory. Attempt any four The intended marks for questions or parts of questions from Section B. questions are given in brackets []. SECTION A (Atempt all questions fromthis Section) Question 1 Choose the correct answers to the questions from the given options. (Do not copy the question, write the correct answers only) () Clockwise moment produced by a force about a fulcrum is considered to be: a) Positive b) Negative i) ii. iv. c) Zero d) None of these Which of the following combinations coIrectly shows the charges on the particles? +1.6 X10-19 C -1.6 X10-19 c+3.2X 10-19 C (a) proton neutron alpha particle (b) alpha particle electron neutron ( ) () proton electron alpha particle alpha particle electron Resistance of (a) (b) (c) (d) Silver Proton decreases with increase in temperature. Copper Germanium Aluminium When light enters from air to glass, it bends toward the normal. If red, blue, and yellow colours are allowed to enter the same glass block at the same angle of which colour, the value of zi-r, be incidence, then for greater? (a) green (b) red (c) blue () yellow [15) by the a explains but but from of K.E P. E the of solid remains molecules remains the following to liquid, the the same.same. statements heat is absorbed p-4 C. p-7" +He TY -Xte - D. 2_eXt (d) phenomenon? (c) (b) (a) body, During (d) (c) Only(bOnlyD ) C (a) There Both Only Only Both Both but t h e KE is P.E K.E its C A change noand temperature & & of of increase D B the the P.E of molecules molecules of state inthe does of the p-7 molecules a P.E increases, increases, not substance and rise. K.E increase. Which X SHeY+ balanced? correctlyare equations B. A. these Vili. medium Vii. relation V. voltage (8) and terminal is for in E.M.F. use) the cell is: the blanks both in microwaves of for filling 3 Vi has mass? zero radiation Which of radiations. types emits Which Choose frequency (d) radiation (cKadioactive ) y(b) B(a) a wavelength. (d) (c) (b) (a) The radiation radiation d) V>8 c) b) a) &=V(always) (always) quantity speedspeed All None of V< the of the UV of > t h e in in correct of source following (when suitable vacuum a above ix. these is indicated ofcones isfour each the from position 4cm, of and12em. 3cm The atwith 9em, d.solid? a 8cm,height C. completcly located cones byare b. depicted, dots a. Which gravitybelow, cone. of On nethe of dhagram eachcenter apex V. What is the ratio of wavelengths between P, Q and R? xi. R (a) xii. 3:2:1 1:2:3 6:3:2 2:3:6 (b) (c) (d) different angles of A student traces the path of a ray of light through a glass prism for incidence. He analyses each diagram and draws the following conclusion: I. On entering the prism, the light ray bends towards its base. emergence II. Light ray suffers refraction at the point of incidence and at the point of while passing through the prism. of the incident ray. III An emergent ray bends at a certain angle to the direction refraction is less IV. While emerging from the prism at the second surface, the angle of than the angle of incidence at that surface. Which of the above inferences are correct? (a) I, II and III (b) I, III and IV (c) II, III and IV (d) All of these. xii. Assertion: A switch will serve the purpose of making and breaking a circuit when it is connected to the neutral wire. Reason: Neutral wire is at zero potential. (a) Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion (b) Both Assertion and Reason are true, but Reason is not the correct explanation of the Assertion (c) Assertion is true, but the Reason is false. (d) Both Assertion & Reason are false. xiv, The magnetic field of clectromagnet can be increase by a) Increasing the number of turns in solenoid b) Increasing the current through the solenoid c) Decreasing the current through the solenoid d) Both (a) & (b) XV. When a body vibrates under a periodic force, the vibrations of the body are always: a) Natural vibrations b) Damped vibrations c) Forced vibrations d) Resonant vibrations Q2 ) (a) Complete the following by choosing the correct answers from the bracket: Vibrations produced in a body under the influence of the periodic force is (forced vibration/resonant vibrations/damped vibrations/sympathetic vibrations) [10] 1 of the earth wire is, According to the old convention the colour (black/green/yellow/red) Lenz's law is based on the law of conservation of (b) (c) 1 (force/charge/mass/energy) has the highest refractive index. (a) (e) (i1) (diamond/glass/water/kerosene oil) (Dyne/Newton/kgf) and it is a S.I. unit of force is 1+1 (vector/scaler) quantity. along the east-west The diagram below shows a copper conductor placedconductor, and Q is below the direction. Magnetic compass P is present above the which of the 2 from A to B, then conductor. If current is passed through the wire why? two compasses will show prominent deflection and Q P Above Below (iii) tracing the path of ray AB The diagram below shows a triangular prism used for diagram and answer the due to the refraction through the prism. Observe the following: 2 S B R P, Q, R and S to see the (a)State the correct eye position from the points through the prism. images of the points Aand B in the same line internal reflection, then (b) If the ray, after entering the prism, suffers total and S to see the image which would be the appropriate position out of P, Q, R, due to TIR? Question 3 are placed near each other as shown in the figure. prisms right-angled isosceles Two (1) right-angled glass prism till it Complete the path of the ray entering the first isosceles [15] 2 emerges from the second identical prism. (1) current protects the electric circuit in case of excess a) which electrical component a switch? and which can also be used as component is connected in an electric b) Name the wire to which this electrical circuit. 2 (ii) The circuit diagram given below represents an electromagnet a) What willbe the polarityof the endX b) Suggest a way by which magnetic ficld of given electromagnet can be increased. COL RHEOSTAT SWITCH BATTERY released when 5.0 kg of steam at 100 C condenses heat of (V) Calculate the heat energv that willbe S.I. unit. (specific latent to form water at (v) 100 C. Express your answer in vaporisation of steam is 2268 kJ/kg). = CD=h. If from point A, It is given that AB= BC freely dropped is m mass of ball A the acccleration due to gravity at the given place is g, 2 (2] +B 1 then what will be its (a) (b) (vi) Potential energy at point A? Kinetic energy at point C? and steel as shown in the A metre rod made of copper are 10 N and 8N respectively. 50 Copper figure. Weight of copper and steel [2] 100 Steel gravity lie (0 to 50 or 50 to 100). On which part does the centre of (a) (b) (vii) 1 [3] Justify your answer lever works. penetrating Name the principle on which a decay of a nucleus, has highest the during enmitted radiation Which (a) (b) in the mass power? above-mentioned radiation result in a change the of emission the Does (c) number? SECTION B (Attempt any four questions) diagram given Question 4 liquid from air as shown in the a enters light monochromatic () A ray of diagram the path of the ray of light after the in show and diagram the a) Copy air. and re-enters the medium of below. strikes the mirror [3] it on the surface of separation whentheray b) Mark in your diagram thetwo angles air. of light moves out from the liquid to Alr Llquld i n Plane Mirror Suggest one way, in each case, by which we can detect the presence of: a) Infrared radiations (i) [31 b) Ultraviolet radiation. c) Give one use of Infrared radiation. Ranbir claims to have obtained an image twice the size of the object with a concave lens. 4) a) Is he correct? Give a reason for your answer. lens b) A lens forms an erect, magnified and virtual image of an object. Name the and draw labelled diagram to show the image formation. (iii) c) Define the power of a lens. d) The lens mentioned in above is of focal length 25cm. calculate the power of the lens. Question 5 onvex. Aeeneave lens of focal length 10 cm is placed at a distance of 60 cm from a screen. How far from the lens should an object be placed so as to obtain a real image on the 1) (3] screen? direction appears to [3] a) A coin kept inside water (u=) when views from air in a vertical be raised by 3.0 mm. find the depth of the coin in water. coin in water. b) How is the critical angle related to the refractive index of the [4] reflected (R)waves from (iii) Examine the graph depicting the transmitted (T) and emitting ultrasonic sounds. Study submarines A and B, which are equipped with a device water is 1500 m/s) the graph and answer the following. (Speed of sound in (i) Dlsplacement T2 10 20 3040 S0 time ins submarine A (a) (b) (c) 20 40 time in s R 60 submarine B Name the device used here. device? Why is ultrasonic sound used in this Calculate the distance of the closest ship? Which submarine is closer to the 1 1 2 submarine. Question 6 block and tackle system hasV.R.=5 A its load and a system indicating the direction of a) draw a neat labelled diagram of effort. kgf. What is the b) Rohan exerts a pullof l50 75% pulley system if its eficiency = maximum load he can raise with this [3] (ii) The graph illustrates the corTelation bctwcen the number of protons (x-axis) and the [3] number of neutrons (y-axis) for clement Cin the periodic table. The element is denoted by letters rather than their conventional symbols. When element C, depicted in the graph, undergoes radioactive decay, it releases radioactive rays. No neutronus 100 Notof protons number Write the chemical symbol along with the mass (a) and atomic number for the 1 element denoted as C'. Plot on the graph, of beta radiation by the element 'C. 1) The daughter element after the emission 1 previous answer, if it undergoes alpha i) The daughter element, as indicated in the decay. km/h and it accelerates to attain a speed [4] 36 of speed a at moving is 1000kg mass A car of (b) (iii) of 108 km/h in 10 seconds calculate. a) the work done by the engine. b) The power of the engine. shouts. Question 7 cliffs and 480 m from the nearest cliff vertical two between standing person A () 3s and the second echo 2s later. Calculate: [3] He hears the first echo after a) the speed of sound. b) The distance of the other cliff from the person. (3] (i) a) Copy and complete the following 22Rn (iii) nuclear reactions: 218 Po + X 844 X, emitted in the above reaction when it is b)What will be the effect on the radiation allowed to pass through am electric field? biological damage? c) Which radiation produces maximum we set T.V. on auto tunning. We are able to see the T.V. channels clearly when a) Which phenomenon led to tunning? the above phenomenon mentioned by you. Define b) phenomenon. c) Give any one more example of this Question 8 operated for is rated at 1000kVA, 220V.ifthe appliance is appliance electrical an a) ) appliance in: kWh and Joule 2 hours, calculate the energy consumed by the Q from the following diagram: b) calculate the equivalent resistance between P and 1012 10 2 20 P [4] the clear visibility of the channels, due to auto [3] (3] (ii) (a) b) (c) (i) What is meant by radioactivity? What is meant by nuclear waste? Suggest one effective process for the safe disposalof nuclear waste. a) drawa labelled diagram of an electric motor. b) What is the function of the split rings in a d.c. motor? c) State one advantage of a.c. over d.c. Question 9 () 5Og of metal piece at 27 C requires 2400J of heat energy so as to attain a temperature of (ii) [4] [3] 327 C. calculate the specific heat capacity of the metal. a) define the term latent heat? [3] b) On what principle does the calorimeter work? c) Some ice is heated at a constant rate, and its temperature is recorded after few (ii) seconds, till steam is formed at 100 C. draw a temperature time graph to represent the change. Label the two-phase change in your graph. A music system draws a current of 400 m when connected to a 12 V battery. (4] a) What is the resistance of the music system? b) The music system is left playing for several hours and finally the battery voltage drops and the music system stops playing when the current drops to 320 mA. At what battery voltage does the music system stop playing? c) Calculate the quantity of heat produced in a 20 2 resistor carrying 2.5 A current in 5 minutes.
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