CLASS: B.Sc. CHEMISTRY & MATHS
12N / 251
St. JOSEPH’S COLLEGE (AUTONOMOUS) TIRUCHIRAPPALLI – 620 002
SEMESTER EXAMINATIONS – NOVEMBER 2012
TIME: 3 Hrs.
MAXIMUM MARKS: 100
SEM
SET
PAPER CODE
TITLE OF THE PAPER
III
2011
11UCH330403A/
11UMA330403A
ALLIED : PHYSICS – I
SECTION – A
Answer all the questions:
20 x 1 = 20
Choose the correct answer:
1.
2.
3.
4.
Velocity of a wave is
a) V = d/t
c) V = f/t
b)
d)
V = t/d
V = f/d
The density of the earth is
a) 5.6 g/cm3
c) 5.2 g/cm3
b)
d)
5.9 g/cm3
5.5 g/cm3
The frequency of ultrasound is
a) Above 15KHz
c) Above 25KHz
b)
d)
Above 20KHz
Above 100MHz
b)
R


d)
R
N

b)
d)
Less than 1
0.99
The resolving power of a grating is
a)
c)
5.
R



R

The  of a transistor is
a) Greater than 1
c) Equal to 1
Fill in the blanks:
6.
The period of SHM is _______.
7.
Acceleration due to gravity in our lab is _______.
8.
Transverse wave is _______.
9.
Focusing
is _______.
the
object
at
different
points
on
the
optic
axis
10.
The reverse bias resistance of a PN junction is _______.
State True or False:
11.
The kinetic energy of an object is due to its motion.
12.
The escape velocity is the speed at which the KE plus the gravitational potential energy of an
object is zero.
13.
Piezo – electric effect is not reversible.
14.
Laurant’s polarimeter is used to determine the specific rotation.
15.
Photo diode is used in object counter.
Answer in one or two sentences:
16.
Define frequency of oscillation.
17.
What is orbital velocity?
18.
Mention any four applications of ultrasonic wave.
19.
What do you mean by chromatic aberration?
20.
What is intrinsic and extrinsic semiconductor?
SECTION – B
Answer all the questions:
21.
a.
5 x 4= 20
Obtain phase – equations of wave motion.
OR
22.
b.
Explain radius of gyration and angular momentum of a body.
a.
State Newton’s law of gravitation and explain.
OR
23.
b.
i) Define stress, strain and young’s modulus.
ii) What is Cantilever?
a.
State and explain the laws of transverse vibration of strings.
OR
24.
b.
Explain any four applications of ultrasonic wave.
a.
Explain the resolving power of a diffraction grating.
OR
b.
With a diagram explain Laurant’s polarimeter.
25.
a.
Explain Zener diode, tunnel diode and photo diode with its symbol.
OR
b.
With a circuit diagram explain the working of a full wave rectifier and mention its
efficiency.
SECTION – C
Answer any FOUR questions:
4 x 15 = 60
26.
Derive an expression for the moment of Inertia of a disc, rod and solid sphere.
27.
Derive an expression for the young’s modulus of a cantilever
i) loaded at one end and
ii) supported at two ends and loaded in the middle.
28.
i) Describe melde’s experiment.
(8)
ii) Draw the circuit diagram of ultrasonic oscillator and explain its
Working.
(7)
29.
Describe a spectrometer and explain how the refractive index of a material can be determined.
30.
With a neat circuit diagram explain the characteristics of a transistor in CE mode.
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