- 1. AMU PAST PAPERSPHYSICS- UNSOLVED PAPER - 1998
2. SECTION I Single Correct Answer Type There are five parts in
this question. Four choices are given for each part and one of them
iscorrect. Indicate you choice of the correct answer for each part
in your answer-book bywriting the letter (a), (b), (c) or (d)
whichever is appropriate 3. 01 Problem 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: a. T2R3.75 b. T2R3/2 c. T2R7/2 d. T2R3 4. 02 Problem 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: a. 52% b.
30% c. 21% d. 10% 5. 03 Problem 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. v22gv2 b. gv2 c. 4gv2 d. 6g 6. 04
Problem A cup of tea cools from 800C to 600 in one minute The
ambient temperature is 300C. In cooing from 600 to 500C. It will
take: a. 80 sec b. 90 sec c. 50 sec d. 60 sec 7. 05 Problem Two
rods of length d1 and d2and coefficient of thermal conductivities
K1 and K2 are kept touching each other both have same area of
crossection. The equivalent thermal conductivity is:d1d2d1d2 a.K1K2
b. K1d1K1d2 d1 d2 c. K1d1 + K2d2 d. K1 + K2 8. 06 Problem 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? a. 170 m b. 750 m c. 670 m d. 570 m 9. 07
Problem 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. 1q2 22 4 0 a21 2 2q2 b.2 4 0 a24q2 c.4 0 a2 3q2 d. 4 0
a2 10. 08 Problem 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?2r a. 33r b. 24r c. 33r d. 4 11. 09
Problem 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. 12. 10 Problem In a Youngs 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: a. 4:3 b. 16:9 c. 9:1
d. 1:7 13. 11 Problem The magnifying power of an astronomical
telescope for relaxed eye is 8 and length of the telescope is 18
cm. If fo and fe br the focal lengths of the objective and the
eyepiece, thus: a. f o=3cm and f e=4cm b. f o=20 and f e=2cm c. f
o=12 and f e=6cm d. f o16 and f e=2cm 14. 12 Problem The material
of a permanent magnet should have, a. High coercivity and low
retentivity b. Low coercivity and high retentivity c. Low
coercivity and high retentivity d. High coercivity and high
retentivity 15. 13 Problem Speed of light in a medium of refractive
index 1.4 is (speed of light in vacuum=3x108 m/sec): a.
2.64x108m/sec b. 2.52x108sec c. 3x108m/s d. 2.14x108 m/sec 16. 14
Problem If we want to produce the electromagnetic waves of
wavelength 500 km by mechanical means, the charge should oscillate
with a frequency of: a. 187 cycles/speed b. 600 cycles/sec c. 550
cycles/sec d. 575 cycles/sec 17. 15 Problem Out of Bi210,U235,U238
and Pu239 the fissionable materials are: a. U235,Pu239 b.
U238,Pu239 c. U235,Pu238 d. U235,Pu235 18. 16 Problem 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
: a. 10 V b. 6 V c. 2 V d. 4 V 19. 17 Problem A small solid ball is
released in a viscous liquid. The velocity of ball is given by a.
Curve D b. Curve C c. Curve B d. Curve A 20. 18 Problem The
displacement time graph of an object is shown in figure. Which part
of graph represents accelerated motion : a. CD b. BC c. AB d. OA
21. 19 Problem 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 : a. 40 cm b. 30 cm c. 20 cm d. 10 cm 22. 20
Problem An open topped rail road car of mass M has an initial
velocity v0 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) :u a. v0 mM Mv0 b. M mtMv0 t c.M
utmutv0 M ut d. 23. 21 Problem Two bodies of mass moving with equal
kinetic energies. The ratio of the magnitude of their respective
linear momenta is : a. 9 : 7 b. 9 : 1 c. 1 : 6 d. 1 : 3 24. 22
Problem 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 = k2rt2, where k is constant. The power
delivered to a prticle by the forces acting on it is a. Zero1 b.
3mk4r2t5 c. 2 mk4r2t5 d. mk2r2t 25. 23 Problem 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) : a. 436 to 486 b. 426 to 584 c. 436 to 586 d.
426 to 586 26. 24 Problem the maximum electric field that can be
held in air without producing Q ionization of air is 107 V/m. The
maximum potential therefore, to which a conducting sphere of radius
0.10 m can be charged in air is : a. 109 V b. 018 V c. 107 V d. 106
V 27. 25 Problem 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 : a. 0.88 r b. 14.56 r2r c. 3 d. 2r 28. 26 Problem In the
circuit the cells E1 and E2 have emf 48 and 8 V and internal
resistances 0.5and 1.0 respectively. Then the potential difference
across cells E1 and E2 will be : a. 4.25 V, 4.25 V b. 3.75 V, 3.75
V c. 4.25 V, 7.5 V d. 3.75 V, 7.5 V 29. 27 Problem 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) a. 37 x 10-3 kg b. 7.61 x 10-3 kg c.
27.61 x 10-3 kg d. 17.61 x 10-3 kg 30. 28 Problem 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 : a. 8 x 1023 MeV b. 6 x 1027 cal c. 9 x
1013 J d. 2 x 107 kWh 31. 29 Problem A vessel of depth 2d cam is
half filled with a liquid of refractive index 1 and the upper half
with a liquid of refractive index . The apparent depth of the
vessel2 seen perpendicular is : 1 a. 2d 1 / 212d b.1 1 2 1 1 c. d 1
2 d. d12 2 32. 30 Problem The absolute refractive indices of glass
and water are respectively. Then the3 4and refractive index of
glass with respect to water will be :2 3 a. 7/6 b. 8/9 c. 9/8 d.
4/3 33. 31 Problem 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 m4m b. 4 ,mm m c. 4 ,4 M d. 2m 34. 32 Problem The truth
table of a logic gate is given as a. NOR gate b. AND gate c. NAND
gate d. XOR gate 35. 33 Problem Energy band gap in a semiconductor
is of the order of : a. 1 eV b. 0.1eV c. 0.5 eV d. none of these
36. 34 Problem A p type semiconductor has : a. More protons as
compared to electrons b. More protons as compared to electrons c.
More holes as compared to electrons d. More electron as compared to
holes 37. 35 Problem Fusion reaction take place at about : a. 3 x
106 K b. 3 x 104 K c. 3 x 103 K d. 3 x 102 K 38. 36 Problem The
unit of 0 ([permeability of free space]) is : a. w b/m2 b. tesla c.
Am2 d. Henry/metre 39. 37 Problem The temperature coefficient of
resistance of material of wire which has a resistance of 140 at
1600C and 240 at 4600 C is : a. 0.000384/0C b. 0.000284/0C c.
0.000184/0C d. none of these 40. 38 Problem 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 : a.
0.30 eV b. 0.20 V c. 0.10 V d. 0.15 V 41. 39 Problem The magnitude
of flux linked with the circuit of resistance 2kvaries with t
second according to equation = 5t2 4t + 12 The induced current in
the circuit at t = 0.2 second is : a. 2 A b. 1 A c. 2 mA d. 1 m A
42. 40 Problem The work done in turning a magnet of magnetic moment
M by an angle of 900 from the meridian is n times. The
corresponding work done to turn it through an angle of 600 where n
is given by : a. 1 b. 1/4 c. 1/2 d. 2 43. 41 Problem The diver at a
depth of 12 cm in water ( = 4/3) sees the sky in a cone of semi
vertical angle : a. 9003 b. sin-1 44 c. tan-4 34 d. sin-1 3 44. 42
Problem 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 : a. tan A1 b. 2cos A c. 2 sin A d. 2 cos A 45. 43 Problem 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 : a. 1 b. 2 c. 3 d. 7 46. 44 Problem 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) : a. 9.9 m b. s 19.9 m c. 29.9 m d. none of these 47.
45 Problem The velocity of sound in a gas at pressure P and density
d is :p a.dp b. d p c. d 2p d.d 48. 46 Problem Mud houses are
colder in summer and warmer in winter becase of : a. clay is a good
conductor of heat b. clay is bad conductor of heat as compared of
with wood and bricks c. clay is neither good conductor nor bad
conductor of heat d. none of these 49. 47 Problem One gram of water
(volume 1 cm3) becomes 1671 cm3 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 = 1.013 x 105 N/m2) : a. 40.3 cal, 499.7 cal b. 50.3
cal, 599.7 cal c. 55.3 cal, 540.7 cal d. none of these 50. 48
Problem The radius of first Bohrs 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) a. 0.53 b. 5.3 c. 0.53 m d. 53 51. 49 Problem Which one of
following series lies in ultra violet region ? a. Balmer series b.
Bracket series c. Paschen series d. Lyman series 52. 50 Problem
Bi210 has a half life of 5 days the time taken for seven/eight of a
sample to decay is : a. 15 days b. 20 days c. 10 days d. 3.4 days
53. FOR SOLUTIONS VISIT WWW.VASISTA.NET
