Hall Ticket No Question Paper Code: AHS007
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
B.Tech I Semester End Examinations (Regular) December, 2016
Regulation: IARE R16
APPLIED PHYSICS
(Common for AE/CE/ME)
Time: 3 Hours 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. Using a suitable diagram explain why when a dielectric is placed in a uniform electric field, the
field within the dielectric weakens?
A parallel plate capacitor having vacuum between the plates is charged such that the surface
charge density on the plates is 8 104C/m2. If a dielectric is now inserted between the plates it
is found that the surface charge density on the dielectric is 6 104C/m2. What is the dielectric
constant of the material
2. Draw a typical hysteresis curve for a ferromagnetic specimen and explain it using the domain
theory.
An empty solenoid having a current of 1A produces a magnetic field of 0.25T at a point along
the axis outside the solenoid. If a specimen is now introduced inside the solenoid then the
magnetic field at the same point on the axis of the solenoid is 25T. What is the susceptibilty of
the specimen?
UNIT II
3. State four factors affecting acoustics of an auditorium and give possible remedies
A cubical hall of dimension L has a reverberation time T. If the size of the hall is shrunk so that
the new dimension is what will be the change in the reverberation time?
4. Describe how ultrasonic waves can be produced by the method of magnetostriction?
A material of thickness Young's modulus Y and density d produces ultrasonic waves of frequency
f. What will be the frequency of the ultrasonic waves produced by another material of
thickness Young's modulus 3Y and density 2d in terms of frequency f.
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UNIT III
5. Two coplanar forces A and B act at a point on a body. Assuming that the angle between the
forces is derive an expression for the resultant. If the resultant makes an angle with the
force write an expression for
A block of mass M=15kg hangs by a cord from a knot K of mass mk. This knot hangs from the
ceiling by means of two cords A and B. If the magnitude of the gravitational force on the knot is
negligible compared to the gravitational force on the block, calculate the tension in cord C given
in figure 1.
Figure 1
6. A uniform horizontal bar is pivoted at its centre of mass. Two forces A and B at distances x1
and x2 of the centre (on either side of the centre) act down wards. What will be the ratio of x1
to x2, if the bar is to remain horizontal? Explain your result.
Three concurrent forces act a point shown in figure 2. If F1 2N, F2 3N, find the magnitude
of F3 assuming that the point is in equilibrium.
Figure 2
UNIT IV
7. What is friction explain the importance and nature of friction.Explain the coefficient friction.

A body slides along down a surface( with a uniform speed) that is inclined at an angle with
respect to the horizontal. If the mass of the body is M and the coefficient of friction between the
body and the surface is then derive a relationship between the coefficient of friction and the
angle
8. How to get solution of problems involving frictional forces with two good examples in detail.

A block weighing 10 KN is kept on a rough horizontal surface,the coefficient of static friction
between the block and horizontal forces is required to start the block moving.
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UNIT V
9. State perpendicular axis theorem. If the moment of inertia of a rectangular plate perpendicular
to its length is ML2/12 and perpendicular to the breadth is MB2/12 then what is the moment
of inertia about the axis passing through the centre of mass and perpendicular to the plane of
the plate?
Obtain an expression for the radius of gyration of a rod of length L about an axis passing through
one end of the rod and perpendicular to the length of the rod
10. Explain the terms torque and angular momentum. Derive relation between torque and angular
momentum.
The moment of inertia of a rectangular plate of mass 1 kg is m2 about an axis passing
through the centre and is perpendicular to the plane of the lamina. The moment of inertia about
an axis passing through midpoint and length is 4 m2 Calculate the dimensions of the
rectangular plate.
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