amu –Past papers: amu –Past papers PHYSICS- UNSOLVED PAPER - 1999
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 The substance which shows no elastic after effect is : Silk Rubber Copper Quartz Problem
Problem: 02 A ball of mass m falls vertically to the ground from a height h 1 and rebound to a height h 2 . The change in momentum of the ball on striking the ground is : mg (h 1 -h 2 ) Problem
Problem: Problem 03 In 1.0 second a particle goes from point A to point B moving in a semicircle of radius 1.0 m figure. The magnitude of the average velocity is : Zero 1.0 m/s 2.0 m/s 3.14 m/s
Problem: Problem 04 In the Young’s double slit experiment . If the width of the slits are in the ratio 4:9. then the ratio of intensity at maxima to the intensity at minima will be : 9:4 25:1 81:16 169:25
Problem: Problem 05 If the earth were the cease rotating about its own axis. The increase in the value of g in C.G.S. system at a place of latitude of 45 0 will be: 2.68 1.68 3.36 0.34
Problem: Problem 06 A transformer is employed to reduce 220 volt to 11 volts. The primary draws a current of 5 A and the secondary 90 A. The efficiency of the transformer is: 90% 45% 75% 20%
Problem: Problem 07 A transistor has an a = 0.95. It has change in emitter current of 1000 mA then the change in collector current is: 95 mA 99.05 mA 100.96 mA 100 mA
Problem: Problem 08 The resistance of a wire at 20 C is 20 ohms and at 500 C is 60 60 ohms. At which temperature its resistance will be 25 ohm? 80 0 C 70 0 C 60 0 C 50 0 C
Problem: Problem 09 Electron can not be constituent of the nueleus because The electron is a negatively charged particle The Compton of wavelength of electron is larger than the size of nucleus The mass of the electron is very small as compred to the mass of the neutron or proton None of these
Problem: Problem 10 Energy E and frequency v of a photon is correctly represented by: a. b. c. d.
Problem: Problem 11 The de Broglie wavelength of thermal neutron at a temperature T K is: a. b. c. d.
Problem: Problem 12 A man in a balloon rising vertically with an acceleration of 4.9m/s 2 releases a ball 2 sec after the balloon is let go from the ground. The greatest height above the ground reached by the ball is: (g = 9.8 m/ s2 ) 24.7 m 7.35 m 28.4 m 14.7 m
Problem: Problem 13 A body of mass M at rest explodes into three masses, two of which are of mass , each are thrown off in perpendicular direction with velocity 3 m/s and 4 m/s respectively the third piece will be thrown off with a velocity of: 3 m/s 2.5 m/s 4.5 m/s 9 m/s
Problem: Problem 14 A wet open umbrella is held vertical and whirled about the handle at a uniform rate of 21 revolution in 44 seconds. If the rim of the umbrella is a circle of 1 m in diameter and the height of the rim above the floor is 4.9 m. The angular speed of the umbrella is: rad /sec 1 rad /sec 1.5 rad /sec 3 rad /sec
Problem: Problem 15 A current of I amp flows through a square loop of wire of side a metre . The magnetic induction at the centre of square loop will be : a. b. c. d.
Problem: Problem 16 One milliwatt of light of wavelength 4560 Å is incident on a caesium surface. The photoelectric current produced, if the quantum efficiency of the surface for photoelectric emission is only 0.5%, will be : 5.8 x 10 -6 amp 0.92 x 10 -6 amp 2.84 x 10 -6 amp 1.84 x 10 -6 amp
Problem: Problem 17 The value of inductance which should be connected in series with a capacitance of 0.5 , resistance of 10 ohm and an A.C source of 50 cps so that the power factor of the circuit is unity, will be : 20.28 H 10.13 H 15.26 H 25.28 H
Problem: Problem 18 Two capacitors of capacitances 8 and 2 are connected in series across a 100 volt D.C. supply. Now if the supply voltage is removed and the capacitors are then connected in parallel. The final charge on each capacitor will be : 2.56 x 10 -4 C, 6.4 x 10 -5 3.56 x 10 -4 C, 7.4 x 10 -5 C 1.4 x 10 -4 C, 5.4 x 10 -5 C none of these
Problem: Problem 19 The amount of work done to increase the temperature of one mole of an ideal gas by 30 0 . if it is expanding under the condition V T 2/3 , will be : 83 J 166 J 106 J 16.6 J
Problem: Problem 20 How many calories of heat will approximately be developed in a 210 watt electric bulb in 5 minutes? Zero 63000 1050 15000
Problem: Problem 21 In the following circuit 5 resistor developes 10.25 cal/s due to a current flowing through it. The heat developed in 2 resistance: 7.31 cal 3.65 cal 8.31 cal 14.32 cal
Problem: Problem 22 Calculate the current through the battery and through a resistance of 6 in the given circuit: 2.66 amp, 2 amp 1.33 amp, 1 amp 0.66 amp, 05 amp none of these
Problem: Problem 23 Two long parallel wires carrying equal current separated 1 m, exert a force of 2x10 -7 N/m on one another. The current flowing through them will be : 1.0 A 2.2 amp 0.5 amp 2 x 10 -7 amp
Problem: Problem 24 Two short magnets are placed on a piece of cork which floats on water. The magnets are so placed, bisects the axis of 9ther at right angles. Then the cork : Has neither translational nor rotational motion Has translational as well as rotational motion Moves along straight line Rotates only
Problem: Problem 25 A paramagnetic substance of susceptibility 3x10 -4 is placed in a magnetic field of 4x10 -1 Am -1 . then intensity of magnetization is : 12 1.33 x 10 8 0.75 x 10 -8 none of these
Problem: Problem 26 A fish looking up through the water sees the out side world contained in a circular horizon. If the refractive index of water is and the fish is 12 cm below the surface. The radius of circle is : cm 12 x cm 12 x 3 x cm 12 x 3 x cm
Problem: Problem 27 Two immiscible liquid of refractive indices 1.5 and are filled in a glass jar each of height 6 cm. A light of source S is at the bottom of the jar. The apparent depth of light source will be : 12.5 cm 17 cm 12 cm 8.5 cm
Problem: Problem 28 125 Water drops of equal radius and equal capacitance C coalesce to form a single drop of capacitance C coalesce to form a single drop of capacitance C’. The relation between C and C’ is : C’ = 5 C C’ = C’ = 125 C
Problem: Problem 29 In a circuit shown two capacitors have identical geometry. But a material of dielectric constant 3 is present between the plates of B. If a battery of emf 10V is connected across the combination the potential difference across S and B will be respectively : 7.5 V, 2.5 V 8.5 V, 3.5 V 5 V, 3.0 V none of these
Problem: Problem 30 Ten tuning forks are arranged in increasing order of frequency in such a way that any two nearest forks produce 4 beats/sec. The highest frequencies is twice that of the lowest possible, lowest and highest frequencies are : 36, 72 Hz 22, 44 Hz 50,100 Hz 40, 80 Hz
Problem: Problem 31 The equation of progressive wave is y = 2 sin (o.5x + 200t) ( x,y in meter). The amplitude and velocity of wave respectively are : 2 cm, 100 cm/sec cm, 0.5 cm/sec 2 cm, 400 cm/sec 0.2 cm, 200 cm/sec
Problem: Problem 32 The radius of earth’s orbit is made one fourth, the duration of a year will become : times times 4 times 8 times
Problem: Problem 33 A man is sitting in a boat which is floating on a pond. If the man drinks some water from the pond, the level of water in the pond : Man decrease or increase dependial on the weight of the man Remains unchanged Increases Decreases
Problem: Problem 34 In an interference pattern produced by the identical coherent sources of monochromatic light, the intensity at the site of central maxima is I. The intensity at the same spot when either of the two slits is closed is I 0 . We must have : I = 4I 0 I and I 0 are related I = 2I 0 I = I 0
Problem: Problem 35 Two lenses of power + 12 and – 2 diopters are placed in contact. What will be the focal length of combination ? 8.33 cm 16.6 cm 12.5 cm 10 cm
Problem: Problem 36 The focal length of the objective and eye piece of a telescope are respectively 200 cm and 5 cm. The maximum magniflying power of the telescope will be : -100 - 60 - 48 - 40
Problem: Problem 37 A gas is compressed at a constant pressure of 50 N/m 2 from a volume of 10 m 3 to a volume of 4 m 3 . Energy of 100 joule is thus added to the gas by heating Its internal energy is : Decreased by 200 J Increased by 100 J Increased by 100 J Increased by 400 J
Problem: Problem 38 The wavelength of maximum energy released during an atomic explosion was 2.93 x 10 -10 m. the maximum temperature attained must be, ( Weins constant = 2.93 x 10 -3 mK ): 5.86 x 10 7 K 10 -13 K 10 -7 K 10 7 K
Problem: Problem 39 Which one of the following is the best observer of thermal radiation : Lamp black White cloth Quartz Flint glass
Problem: Problem 40 Two metallic blocks A and B of thermal conductivities 4 K and K are connected as shown in the figure. The length of the blocks are L and respectively, then equivalent thermal conductivity of combination of two blocks is : 2 K 9 K K 3 K
Problem: Problem 41 The least velocity required to throw a body away from the surface of a planet, so, that it may not return is (radius of the planet is 6.4 x 10 6 m, g = 9.8 m/s 2 ) 11.2 x 10 3 m/sec 15.0 x 10 3 m/sec 12.8 x 10 3 m/sec 9.8 x 10 3 m/sec
Problem: Problem 42 A body of mass 2 kg is released at the top of smooth inclined plane having inclination 30 0 . It takes 3 second to reach the bottom. If the inclination is doubled keeping same height (i.e., made 60 0 ), the time taken will be : 1.5 sec sec 3 sec 3 sec
Problem: Problem 43 A ball is dropped from the top of building at the same instant another ball is thrown vertically upwards from the ground level the ball collide 2 second later. The height of the building is : 72 m 54 m 18 m 36 m
Problem: Problem 44 A projectile can have the same range for two angle of projection. If h 1 and h 2 are maximum heights when the range in the two case is R, then the relation between R, h 1 and h 2 will be R = 4 R = 2 R = R =
Problem: Problem 45 The potential energy of particle in a certain field is given by where a, and b are positive constants and r is the distance from the centre of the filed. The distance of the particle in the stable equilibrium position is : a. - b. c. d.
Problem: Problem 46 A gun weighing 5 kg fires a bullet of mass 10 -2 kg with a speed of 5 x 10 2 m/s. What is the kinetic energy of the bullet and gun will respectively ? 1.25 x 10 3 J, 2.5 J 2.25 x 10 3 J, 3.5 J 0.25 x 10 3 J, 1.5 J none of these
Problem: Problem 47 The maximum wavelength of radiation that can produce photoelectric effect in a certain metal is 200 n m. The maximum Kinetic Energy acquired by the electrons due to radiations of wavelength 100 nm will be : 200 eV 100 eV 6.2 eV 12.4 eV
Problem: Problem 48 Light of frequency 5 v 0 fall on a photosensitive surface of the solid frequency v 0 . The velocity of emitted electrons is 4 x 10 5 m/s. If now light of frequency 9v 0 is incident on the surface, then velocity of electron will become : 5.64 x 10 5 m/s 7.2 x 10 5 m/s 8 x 10 5 m/s 2 x 10 5 m/s
Problem: Problem 49 A star initially has 1040 deuterons. It produces energy n a the process 1 H 2 + 1 H 2 1 H 3 + p 1 H 2 + 1 H 3 2 H 4 + n If the average power radiated by the star is 10 16 =2.014 amu , M(n) = 4.001 amu , M(m) = 1.008 amu M(He 4 ) = 4.001 amu the deuteron supply of the star is exhausted in the time of the order of the : 10 16 sec 10 12 sec 10 6 sec 10 8 sec
Problem: Problem 50 The type of bonding in silicon crystal is : Vander walls Covalent Ionic Metallic
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