This document contains a physics exam from 2006 with 40 multiple choice questions covering topics like: 1) Sound waves and the Doppler effect 2) Electric currents and magnetic fields 3) Thermal properties of materials 4) Optics including lenses, mirrors, and the photoelectric effect The questions are in a single-answer multiple choice format testing conceptual understanding of core physics principles. The document provides context for understanding physics exam questions from over 15 years ago.

1. AMU –PAST PAPERS
PHYSICS- UNSOLVED PAPER - 2006

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 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

3. 01 Problem
The difference between the apparent frequency of a source of sound as
perceived by the observer during its approach and recession is 20% of the
frequency of the source. If the speed of sound in air is 300 ms-1, the velocity of
the source is :
a. 1.5 ms-1
b. 12 ms-1
c. 6 ms-1
d. 3 ms-1

4. 02 Problem
Three long straight wires A, B and C are carrying currents as shown in figure.
Then the resultant force on B is directed :
a. Perpendicular to the plane of paper and outward
b. Perpendicular to the plane of paper and inward
c. Towards A
d. Towards B

5. 03 Problem
Curie-Weiss law is obeyed by iron :
a. At curie temperature only
b. At all temperatures
c. Below Curie temperature
d. Above Curie temperature

6. 04 Problem
A magnet N-S is suspended from a spring and when it oscillates, the magnet
moves in and out of the coil C. The coil is connected to a galvanometer G. Then,
as the magnet oscillates:
a. G shows no deflection
b. G shows deflection to the left and right but the amplitude steadily
decreases
c. G shows deflection to the left and right with constant amplitude
d. G shows deflection on one side

7. 05 Problem
The dimensional formula for inductance is:
a. [ML2T-2A-2]
b. [ML2TA-2]
c. [ML2T-1A-2]
d. [ML2T-2A-1]

8. 06 Problem
The maximum current that can be measured by a galvanometer of resistance
40ohm is 10mA. It is converted into a voltmeter that can read upto 50 V. The
resistance to be connected in series with the galvanometer (in ohms) is:
a. 2010
b. 4050
c. 5040
d. 4960

9. 07 Problem
When a body falls in air, the resistance of air depends to a great extent on the
shape of the body. 3 different shapes are given. Identify the combination of air
resistances which truly represents the physical situation?
(The cross-sectional areas are the same).
a. 1<2<3
b. 2<3<1
c. 3<2<1
d. 3<1<2

10. 08 Problem
Heavy water is
a. A compound of deuterium and oxygen
b. Water at 40C
c. Water, in which soap does not lather
d. Compound of heavy oxygen and heavy hydrogen

11. 09 Problem
A bullet moving with a speed of 100ms-1 can just penetrate two planks of equal
thickness. Then, the number of such planks penetrated by same bullet when the
speed is doubled will be
a. 6
b. 10
c. 4
d. 8

12. 10 Problem
Absorption coefficient of an open window is
a. 1
b. 0.25
c. zero
d. 0.5

13. 11 Problem
In Meld's experiment in the transverse mode, the frequency of the tuning fork
and the frequency of the waves in the string are in the ratio:
a. 2 :1
b. 4:1
c. 1:1
d. 1:2

14. 12 Problem
An unknown resistance R1 is connected in series with a resistance of 10 . This
combination is connected to one gap of meter bridge while a resistance R2 is
connected in the other gap. The balance point is at 50 cm. Now, when the 10
resistance is removed the balance point shifts to 40 cm. The value R1(in ohms) is:
a. 20
b. 10
c. 60
d. 40

15. 13 Problem
In the circuit shown, the internal resistance of the cell is negligible. The steady
state current in the 2 resistor is :
a. 0.6 A
b. 1.2 A
c. 0.9 A
d. 1.5 A

16. 14 Problem
A rectangular coil of 300 turns has an average area of 25 cm x 10 cm. The coil
rotates with a speed of 50 cps in uniform magnetic field of strength 4 x 10-2 T
about an axis perpendicular to the field. The peak value of the induced emf (in
volt) is :
a. 300
b. 3000
c. 3
d. 30

17. 15 Problem
In a LCR circuit the potential difference between the terminals of their inductance
is 60 V, between the terminals of the capacitor is 30 V and that between the
terminals of resistance is 40 V. The supply voltage will be equal to :
a. 130 V
b. 10 V
c. 50 V
d. 70 V

18. 16 Problem
A thread is tied slightly loose to a wire frame as in figure and the frame is dipped
into a soap solution and taken out. The frame is completely covered with the film.
When the portion A is punctured with a pin, the thread :
a. Becomes concave towards A
b. Becomes convex towards A
c. Either (a) or (b) depending on the size of A with respect to B
d. Remains in the initial position

19. 17 Problem
Oxygen is 16 times heavier then hydrogen. Equal volumes of hydrogen and
oxygen are mixed. The ratio of speed of sound in the mixture to that in
hydrogen is :
a. 8
2
b. 17
1
c. 8
32
d. 17

20. 18 Problem
The relationship between the force F and position x of a body is as shown in
figure. The work done in displacing the body from x = 1m to x = 5 m will be :
a. 30 J
b. 15 J
c. 25 J
d. 20 J

21. 19 Problem
Specific rotation of sugar solution is 0.01 SI units. 200 kgm-3 of impure sugar
solution is taken in a polarimeter tube of length 0.25 m and an optical rotation of
0.4 rad is observed. The percentage of purity of sugar in the sample is :
a. 11 %
b. 20 %
c. 80 %
d. 89 %

22. 20 Problem
In a forward biased p-n junction diode, the potential barrier in the depletion
region is of the form :
a.
b.
c.
d.

23. 21 Problem
From the adjacent figure, the correct observation is :
a. The pressure on the bottom of tank A is greater than at the bottom of B
b. The pressure on the bottom of the tank a is smaller than at the bottom of B
c. The pressure depends on the shape of the container
d. The pressure on the bottom of A and B is the same

24. 22 Problem
The electric bulbs A and B are rated as 60 W and 100 W. They are connected in
parallel to the same source. Then :
a. B draws more current than A
b. Currents drawn are in the ratio of their resistances
c. Both draw the same current
d. A draws more current than B

25. 23 Problem
A thin plano-convex lens acts like a concave mirror of focal length 0.2 m when
silvered from its plane surface. The refractive index of the material of the lens is
1.5. The radius of curvature of the convex surface the lens will be :
a. 0.1 m
b. 0.57 m
c. 0.4 m
d. 0.2 m

26. 24 Problem
A balloons rising vertically up with a velocity of 29 ms-1. A stone is dropped from it
and it reaches the ground in 10 s. The height of the balloon when the stone was
dropped from it is : (g = 9.8 ms-1)
a. 400 m
b. 150 m
c. 100 m
d. 200 m

27. 25 Problem
In a Young’s double slit experiment, the separation between the two slits is 0.9
mm and the fringes are observed 1 m away. If it produces the second dark fringe
at a distance of 1 mm from the central fringe, the wavelength of the
monochromatic source of light used is :
a. 450 nm
b. 400 nm
c. 500 nm
d. 600 nm

28. 26 Problem
H-polaroid is prepared by :
a. Orienting herapathite crystal in the same direction in nitrocellulose
b. Using thin tourmaline crystals
c. Stretching polyvinyl alcohol and then heated with dehydrating agent
d. Stretching polyvinyl alcohol and then impregnating with iodidne

29. 27 Problem
A spherical drop of capacitance 1 is broken into eight drops of equal radius.
Then, the capacitance of each small drop is :
1
a. μF
2
1
μF
b. 4
1
μF
c. 8
d. 8 μF

30. 28 Problem
Identify the wrong description of the below figures :
a. 1 reprsents far-sightedness
b. 2 correction for short-sightedness
c. 3 represents far-sightedness
d. 4 correction for far-sightedness

31. 29 Problem
Threshold wavelength for photoelectric emission from a metal surface is 5200 Å.
Photoelectrons will emitted when this surface is illuminated with monochromatic
radiation from :
a. 1 W IR lamp
b. 50 W UV lamp
c. 50 W IR lamp
d. 10 W IR lamp

32. 30 Problem
The electric flux for Gaussian surface A that enclose the charged particles in free
space is (given q1 = -14 nC, q2 = 78.85 nC, q3 = -56 nC)
a. 103Nm2C-1
b. 103CN-1m-2
c. 6.32 x 103 NM2C-1
d. 6.32 x 103 CN-1 m-1

33. 31 Problem
Which state of triply ionized beryllium (Be3+) has the same orbital radius as that
of the ground state of hydrogen ?
a. n = 3
b. n = 4
c. n = 1
d. n = 2

34. 32 Problem
If M is the atomic mass and A is the mass number, packing fraction is given by :
M
a.
M A
M A
b. A
A
c. M A
A M
d. A

35. 33 Problem
A count are metre shows a count of 240 per minute from a given radioactive
source later the metre shows a count are of 30/ min. The half-life of the source is
:
a. 80 min
b. 120 min
c. 20 min
d. 30 min

36. 34 Problem
An uncharged sphere of metal is placed inside a charged parallel plate capacitor.
The lines of force will look like :
a.
b.
c.
d.

37. 35 Problem
A current flows in a conductor from east to west. The direction of the magnetic
field at a point above the conductor is :
a. Towards east
b. Towards west
c. Towards north
d. Towards south

38. 36 Problem
Excitation energy of a hydrogen like in its first excitation state is 40.8 eV. Energy
needed to remove the electron from the ion in ground state is :
a. 40.8 eV
b. 27.2 eV
c. 54.4 eV
d. 13.6 eV

39. 37 Problem
An ideal gas heat engine operates in Carmot’s cycle between 2270C and 1270C. It
absorbs 6 x 104 J at high temperature. The amount of heat converted into work is
:
a. 1.6 x 104 J
b. 1.2 x 104 J
c. 4.8 x 104 J
d. 3.5 x 104 J

40. 38 Problem
Which one of the following graphs represents the behaviour of an ideal gas ?
a.
b.
c.
d.

41. 39 Problem
A beam of parallel rays is brought to focus by a plano-convex lens. A thin concave
lens of the same focal length is joined to the first lens. The effect of this is :
a. The focus shifts to infinity
b. The focal point shifts towards the lens by a small distance
c. The focal point shifts away from the lens by a small distance
d. The focus remains undisturbed

42. 40 Problem
Effective capacitance between A and B in the figure, shown is :
3'
a. μF
14
b. 14 μF
3
c. 21 μF
μF
d. 23

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