amu –Past papers: amu –Past papers PHYSICS- UNSOLVED PAPER - 1998
SECTION – I: SECTION – I Single Correct Answer Type There are five parts in this question. Four choices are given for each part and one of them is correct. Indicate you choice of the correct answer for each part in your answer-book by writing the letter (a), (b), (c) or (d) whichever is appropriate
Problem: 01 Imagine a light planet resolving around a very massive star in a circular orbit of radius R with a period of resolution T. If the gravitational force attraction between the planet and the star is proportional to R -5/2 then: T 2 R 3.75 T 2 R 3/2 T 2 R 7/2 T 2 R 3 Problem
Problem: 02 A simple pendulum is executing simple harmonic motion with a time period T. If the length of the pendulum is increased by 21% the increase in the time period of the pendulum of increased length is: 52% 30% 21% 10% Problem
Problem: Problem 03 A ball is moving horizontal with speed v strikes the bob of a simple pendulum at rest. The mass of the bob is equal to that of ball. If the collision is elastic, the bob will rise to height is: a. b. c. d.
Problem: Problem 04 A cup of tea cools from 80 0 C to 60 0 in one minute The ambient temperature is 30 0 C. In cooing from 60 0 to 50 0 C. It will take: 80 sec 90 sec 50 sec 60 sec
Problem: Problem 05 Two rods of length d 1 and d 2 and coefficient of thermal conductivities K 1 and K 2 are kept touching each other both have same area of crossection . The equivalent thermal conductivity is: K 1 d 1 + K 2 d 2 K 1 + K 2
Problem: Problem 06 Assume that a piece of bread supplies 200k cal of heat to you. If your weight is 60 kg and efficiency is 40% then how much you can climb up by using this energy? 170 m 750 m 670 m 570 m
Problem: Problem 07 Equal charges q are placed at the four corners A,B,C,D of a square of length a, the magnitude of the force on the charge at D will be : a. b. c. d.
Problem: Problem 08 The two fixed changes +4q and +q are at a distance r apart. At what point between these charges +q must be placed to keep in a equilibrium? a. b. c. d.
Problem: Problem 09 The magnetic flux density B at a distance r from a long straight wire carrying a steady current varies with distance r as shown in : a. b. c. d.
Problem: Problem 10 In a Young’s double slit experiment the interference pattrerns is found to have an intensity ratio between bright and dark fringes a 16:9. It implies that the amplitude ratio of the interfering rays is: 4:3 16:9 9:1 1:7
Problem: Problem 11 The magnifying power of an astronomical telescope for relaxed eye is 8 and length of the telescope is 18 cm. If f o and f e br the focal lengths of the objective and the eyepiece, thus: f o =3cm and f e =4cm f o =20 and f e =2cm f o =12 and f e =6cm f o 16 and f e =2cm
Problem: Problem 12 The material of a permanent magnet should have, High coercivity and low retentivity Low coercivity and high retentivity Low coercivity and high retentivity High coercivity and high retentivity
Problem: Problem 13 Speed of light in a medium of refractive index 1.4 is (speed of light in vacuum=3x10 8 m/sec): 2.64x10 8 m/sec 2.52x10 8 sec 3x10 8 m/s 2.14x10 8 m/sec
Problem: Problem 14 If we want to produce the electromagnetic waves of wavelength 500 km by mechanical means, the charge should oscillate with a frequency of: 187 cycles/speed 600 cycles/sec 550 cycles/sec 575 cycles/sec
Problem: Problem 15 Out of Bi 210 ,U 235 ,U 238 and Pu 239 the fissionable materials are: U 235 ,Pu 239 U 238 ,Pu 239 U 235 ,Pu 238 U 235 ,Pu 235
Problem: Problem 16 The maximum kinetic energy of photoelectrons emitted from a surface when photons of energy 6 eV fall on a is 4 eV . the stopping potential is : 10 V 6 V 2 V 4 V
Problem: Problem 17 A small solid ball is released in a viscous liquid. The velocity of ball is given by Curve D Curve C Curve B Curve A
Problem: Problem 18 The displacement time graph of an object is shown in figure. Which part of graph represents accelerated motion : CD BC AB OA
Problem: Problem 19 A mass of 200 g when suspended from a massless spring extends it by 10 cm. A lump of plasticine of mass 200 g is dropped from rest onto a massless pan from a height of a 40 cm as shown in figure. As a result the pan moves downwards through a maximum distance of : 40 cm 30 cm 20 cm 10 cm
Problem: Problem 20 An open topped rail road car of mass M has an initial velocity v 0 along a straight horizontal frictionless track. It suddenly starts raising at time t = 0. The rain drops fall vertically with velocity u and add a mass m kg/sec of water. The velocity of car after t second will be (assuming that it is not completely filled with water) : a. b. c. d.
Problem: Problem 21 Two bodies of mass moving with equal kinetic energies. The ratio of the magnitude of their respective linear momenta is : 9 : 7 9 : 1 1 : 6 1 : 3
Problem: Problem 22 A particle of mass m is moving in a circular path of constant radius r such that its centripetal acceleration as it varying with time to as ac = k 2 rt 2 , where k is constant. The power delivered to a prticle by the forces acting on it is Zero mk 4 r 2 t 5 2 mk 4 r 2 t 5 mk 2 r 2 t
Problem: Problem 23 A whistle of frequency 500 Hz tied to the end of spring of length 1.2 m revolves at 400 rev./minute. A listener standing some distance away in the plane of rotation of whistle, hears frequency in the range (speed of second = 34 m/s) : 436 to 486 426 to 584 436 to 586 426 to 586
Problem: Problem 24 the maximum electric field that can be held in air without producing Q ionization of air is 10 7 V/m. The maximum potential therefore, to which a conducting sphere of radius 0.10 m can be charged in air is : 109 V 01 8 V 10 7 V 10 6 V
Problem: Problem 25 In the fig given below, find the resistance between parts A and B. both the circles and the diameter are made of uniform wire of resistance r ohm per metre . The length AB is 2 metre : 0.88 r 14.56 r 2 r
Problem: Problem 26 In the circuit the cells E 1 and E 2 have emf 48 and 8 V and internal resistances 0.5 and 1.0 respectively. Then the potential difference across cells E 1 and E 2 will be : 4.25 V, 4.25 V 3.75 V, 3.75 V 4.25 V, 7.5 V 3.75 V, 7.5 V
Problem: Problem 27 In producing chlorine through electrolysis 100 kW power at 125 V is being consumed. How much chlorine per minute is liberated ? (E.C.E of chlorine = 0.36 x 10 -6 kg/C) 37 x 10 -3 kg 7.61 x 10 -3 kg 27.61 x 10 -3 kg 17.61 x 10 -3 kg
Problem: Problem 28 How much energy will approximately be released if all the atom of 1 kg of deuterium could undergo fusion ? Assume in the fusion of deuterium 0.1% mass is converted into energy : 8 x 10 23 MeV 6 x 10 27 cal 9 x 10 13 J 2 x 10 7 kWh
Problem: Problem 29 A vessel of depth 2d cam is half filled with a liquid of refractive index and the upper half with a liquid of refractive index . The apparent depth of the vessel seen perpendicular is : a. b. c. d.
Problem: Problem 30 The absolute refractive indices of glass and water are respectively. Then the refractive index of glass with respect to water will be : 7/6 8/9 9/8 4/3
Problem: Problem 31 A wire of magnetic moment M and pole strength m is cut in to four pieces. If one of the part is bent in the form of a semcircle . Its magnetic moment and pole strength, respectively are : a. M b. ,m c. , d. m
Problem: Problem 32 The truth table of a logic gate is given as NOR gate AND gate NAND gate XOR gate
Problem: Problem 33 Energy band gap in a semiconductor is of the order of : 1 eV 0.1eV 0.5 eV none of these
Problem: Problem 34 A p type semiconductor has : More protons as compared to electrons More protons as compared to electrons More holes as compared to electrons More electron as compared to holes
Problem: Problem 35 Fusion reaction take place at about : 3 x 10 6 K 3 x 10 4 K 3 x 10 3 K 3 x 10 2 K
Problem: Problem 36 The unit of ([permeability of free space]) is : w b/m 2 tesla Am 2 Henry/ metre
Problem: Problem 37 The temperature coefficient of resistance of material of wire which has a resistance of 140 at 160 0 C and 240 at 460 0 C is : 0.000384/ 0 C 0.000284/ 0 C 0.000184/ 0 C none of these
Problem: Problem 38 An aircraft with a wing span of 20 m flies at a horizontal speed of 360 km/h in a region where the vertical component of the earth field is 5 x 10 -5 tesla . The potential difference between the tips of the wing will be : 0.30 eV 0.20 V 0.10 V 0.15 V
Problem: Problem 39 The magnitude of flux linked with the circuit of resistance 2k varies with t second according to equation = 5t 2 – 4t + 12 The induced current in the circuit at t = 0.2 second is : 2 A 1 A 2 mA 1 m A
Problem: Problem 40 The work done in turning a magnet of magnetic moment M by an angle of 90 0 from the meridian is n times. The corresponding work done to turn it through an angle of 60 0 where n is given by : 1 1/4 1/2 2
Problem: Problem 41 The diver at a depth of 12 cm in water ( = 4/3) sees the sky in a cone of semi vertical angle : 90 0 sin -1 tan -4 sin -1
Problem: Problem 42 Angle of prism is A and its one surface is silvered, light rays falling at an angle of incidence 2 a on first surface return back through the same path after suffering reflections at second silvered surface refractive index of the material of the prism will be : tan A cos A 2 sin A 2 cos A
Problem: Problem 43 A glass tube 1.0 m long is filled with water. The water can be drained out slowly at the bottom of the tube. If a vibrating tuning fork of frequency 500 cycles/sec is brought at the upper end of the tube and the velocity of sound is 330 m/s, then the total number of resonance obtained will be : 1 2 3 7
Problem: Problem 44 A stone is dropped into a well and its splash is heard at the mouth of the well after an internal of 1.45 second. The depth of the well is (Given that velocity of send in air at room temperature is equal to 332 m/s) : 9.9 m s 19.9 m 29.9 m none of these
Problem: Problem 45 The velocity of sound in a gas at pressure P and density d is : a. b. c. d.
Problem: Problem 46 Mud houses are colder in summer and warmer in winter becase of : clay is a good conductor of heat clay is bad conductor of heat as compared of with wood and bricks clay is neither good conductor nor bad conductor of heat none of these
Problem: Problem 47 One gram of water (volume 1 cm 3 ) becomes 1671 cm 3 of steam when boiled at a pressure of one atmosphere. The latent heat of vaporization is 540 cal/g. The external work done and increase in internal energy will be (1 atmosphere = 1.01 3 x 105 N/m 2 ) : 40.3 cal, 499.7 cal 50.3 cal, 599.7 cal 55.3 cal, 540.7 cal none of these
Problem: Problem 48 The radius of first Bohr’s orbit of electron in hydrogen atom is : (e = 1.6 x 10 -19 C, m = 9.1 x 10 -31 kg, h = 6.6 x 10 -34 Js) 0.53 Å 5.3 Å 0.53 m 53 Å
Problem: Problem 49 Which one of following series lies in ultra violet region ? Balmer series Bracket series Paschen series Lyman series
Problem: Problem 50 Bi 210 has a half life of 5 days the time taken for seven/eight of a sample to decay is : 15 days 20 days 10 days 3.4 days
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