Download 12021 14115 3 Hours / 100 Marks Seat No.

12021
14115
3 Hours / 100 Marks
Instructions –
Seat No.
(1) All Questions are Compulsory.
(2) Answer each Section on separate answer sheet.
(3) Answer each next main Question on a new page.
(4) Illustrate your answers with neat sketches wherever
necessary.
(5) Figures to the right indicate full marks.
(6) Assume suitable data, if necessary.
(7) Use of Non-programmable Electronic Pocket
Calculator is permissible.
(8) Mobile Phone, Pager and any other Electronic
Communication devices are not permissible in
Examination Hall.
Marks
SECTION – I
1.
Attempt any NINE of the following:
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a) State the relation between electric field intensity and electric
flux density. Give significance of each term involved.
b) Why earth is considered at zero potential?
c) For a silica optical fibre the refractive index of core layer is
1.56 and that of cladding is 1.35. Calculate the critical angle.
P.T.O.
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[2]
Marks
d) State the conditions for total internal reflection.
e) Draw energy band diagram for conductors and semiconductor.
f)
When a charge of 0.04 micro coulomb is given to a capacitor
its potential is raised to 200 volts. Find its capacitance.
g) What is the effect of temperature on the conductivity of
semiconductor?
h) Define the term.
(i)
Nanoscale
(ii)
Nanoparticles
i)
State coulomb’s inverse square law.
j)
Define capacitance. State its SI unit.
k) Give any two applications of optical fibre.
Attempt any FOUR of the following:
2.
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a) Obtain an expression for intensity of electric field at a point
in an electric field of charge Q coulomb, placed in a medium
of dielectric constant K.
b) Define electric lines of force. State its any three properties.
c) A sphere of radius 20 cm is given a charge of 1600 microcoulomb
and placed in air. Find the intensity of electric field:
(i)
at a point 60 cm from the centre of the sphere.
(ii)
at a point on the surface of the sphere.
d) Two electric charges of 33 microcoulomb and –55 micro
coulomb are situated 1.6 m apart in air. Determine the position
of the point in between them where potential due to both
charges is zero.
e) Explain the propagation of light through a optical fibre.
f)
Define acceptance angle, critical angle numerical aperture. State
formula to calculate numerical aperture.
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Marks
Attempt any FOUR of the following:
3.
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a) Derive an expression for the capacitance of a parallel plate
capacitor.
b) Two condensers have an equivalent capacitance of 24
microfarad when connected in parallel and 2.25 microfarad
when connected in series. Calculate the individual capacitance.
c) Distinguish between P-type and N-type semiconductor.
d) Give one application each of nanotechnology in electronics,
automobile.
e) Define forbidden energy gap. Draw energy band diagram for
conductor semiconductor and insulators.
f)
Derive an expression for the resultant capacitance, when
condensers are connected in series.
P.T.O.
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[4]
Marks
SECTION – II
4.
Attempt any NINE of the following:
18
a) What is buffer solution? Give types of buffer solutions.
b) How batteries are classified?
c) Define electrochemical cell and closed circuit voltage.
d) How are the insulating materials classified?
e) Define adhesives and write two examples.
f)
Name four important ores of copper with formula.
g) Write two physical properties and two applications of
Alluminium.
h) Define immersed corrosion. Give one example.
i)
Which oxide film is protective against corrosion? Why?
j)
Why galvanized containers are not used for food storage?
k) Write two types of stable oxide film.
5.
Attempt any FOUR of the following:
a) What is effect of dilution on specific conductivity?
b) Explain the construction and working of Ni-Cd storage cell
with neat labelled diagram.
c) Draw a neat labelled diagram of H2-O2 fuel cell. Write
electrode reaction.
d) What are the advantages and limitations of fuel cell?
e) Write two properties and applications of phenol formaldehyde
and epoxy resin.
f)
What are ceramics? Give their classification on the basis of
it’s uses.
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Marks
Attempt any FOUR of the following:
6.
a) Explain the process of smelting of copper ore in the blast
furnace.
b) Describe electrolytic reduction of alumina.
c) Write composition, properties and applications of following
alloys:
(i)
Rose metal
(ii)
Tinmann’s solder.
d) Define Sherardizing. State and explain the principle of
Sherardizing.
e) Name and explain the process of protecting steel article from
corrosion by coating tin over it.
f)
Describe hydrogen evolution mechanism of immersed corrosion.
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