Hall Ticket No Question Paper Code: AHS007
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
Four Year B.Tech I Semester Supplementary Examinations July, 2018
Regulation: IARE R16
APPLIED PHYSICS
Time: 3 Hours (Common to AE ME CE) Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. Derive an expression for internal field in case of one dimensional array of atoms in dielectric
solids.
If a NaCl crystal is subjected to an electricfield of 1000 V/m and the resulting polarization is
cm2.calculate the relative permeability of NaCl.
2. Explain the domain theory of Ferro magnetism on the basis of hysteresis curve.
A silicon material is subjected to a magnetic field of strength 1000 A/m. If the magnetic susceptibility
of silicon is -0.3 x calculate its magnetization. Also evaluate the magnetic flux
density of the field inside the material.
UNIT II
3. What are the conditions for an acoustic design of a hall? Explain the major factors in the acoustic
design of a hall.
The reverberation time is found to be 1.5 sec for an empty hall and it is found to be 1 sec when
a certain cloth of 20 m2 is suspended at the centre of the hall. If the dimensions of the hall are
10x8x6 m3, calculate the coefficients of absorption of certain cloth.
4. What are ultrasonic waves? Mention their properties. Explain with suitable diagram the production
of ultrasonic waves using piezoelectric effect.
Calculate the natural frequency of ultrasonic waves using the following data. Thickness of the
crystal is Young's modulus of the quartz is 8.0x1010 N/m2 and density is 2.65 x103
kg/m3.
UNIT III
5. State and explain Triangle law of forces. Write the expression for resultant using law of forces.

Two forces acting on a body are 500N and 1000 N making an angle with 300 with X axis and Y
axis respectively. Determine the third force such that the resultant of all the three forces is 1000
N directed at 450 to X-axis.
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6. State and explain Varignon's theorem, with an example.
A traffic light weighing 122 N hangs from a cable tied to two other cables fastened to a support
with the upper cables make angles of 370 and 530 with the horizontal. These upper
cables are not as strong as the vertical cable and will break if the tension in them exceed 100 N.
Does the traffic light remain hanging in this situation, or will one of the cables break?
UNIT IV
7. Explain a body in equilibrium on a smooth inclined plane under the action of force and on a
rough inclined plane with suitable diagram .
The force required to pull a body up a plane inclined to the horizontal at angle of 18:130 is 105
N and the force required to pull it down the plane,10 N. what is the weight of the body and the
coefficient of friction between its surface and that of the plane.
8. Explain the usefulness of friction in daily life with suitable examples.
A load of 24 kg lies on a plane inclined at an angle of 170 to the horizontal, the coefficient of
friction for the surfaces of the two being 0.36.Calculate the least horizontal force required to make
the load move up and down the plane.
UNIT V
9. Explain the general theorem of moment of inertia of a plane laminar body and three dimensional
body for parallel axes.
Find the moment of inertia of a rectangular lamina
i. About an axis through its centre and parallel to one of its axis
ii. About one side.
10. Explain the general theorem of moment of inertia of perpendicular axis for a three dimensional
body.
Obtain the moment of inertia of thin uniform rod
i. About an axis through its centre and perpendicular to its length
ii. About an axis passing through one end of the rod and perpendicular to its length.
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