Maharashtra State Board of Techni cal Education-Applied Science

Maharashtra State Board of Technical Education
Course Name: Electrical and Electronics Engineering Group
Course Code: EE/EP and ET/EJ/EN/EX/IE/IS/IC/DE/EV/MU/ IU/ED/EI
Semester :- Second
Subject: - Applied science Subject Code: - 9008
Duration: 3 Hours (For Both Sections together) Marks - 80

Section - I

Instructions: - 1) All questions are Compulsory.
2) Draw neat labeled diagrams wherever necessary.
3) Use of non-programmable calculator is allowed.

Q.1) Attempt any Eight of the following: (8x2=16)
1) State Coulomb’s inverse square law.
2) Define dielectric strength, breakdown potential.
3) State types of condenser.
4) State any two applications of optical fibres.
5) Define capacitance, state its SI unit.
6) Draw the configuration of an optical fibre.
7) Define valence band, Fermi energy.
8) Draw energy level diagram for Insulator & semiconductor.
9) A fibre has a core diameter of 4 mm & its core refractive index is 1.43. The
refractive index of cladding is 1.415. Determine Numerical aperture.
10) What is current density in pure semi conductor?
11) When germanium is doped with aluminum, is the result n-type or p-type
semiconductor? Give reason.

Q.2) Attempt any Three of the following: (3x4=12)
1) State any four properties of electric lines of force.
2) Derive an expression for potential due to point charge.
3) Find the equivalent capacitance for the combination of capacitors shown
below(see attachment below for diagram).
Where C1 = 12.0 mF, C2 = 5.30 mF, C3 = 4.50
mF
4) Two point charges 16 mc & 64 mc are
placed 3 m apart in air. Find the
position of point in between them
where intensity due to two charges is equal.

Q.3) Attempt any Three of the following: (3x4=12)
1) State formula to find potential of the earth.
A sphere of diameter 8 cm is placed in the medium of dielectric constant 1.2
and is given charge of 0.024 mc. Find potential at its surface.
2) What is Numerical aperture? Explain with the labeled diagram. State formula to
find numerical aperture.
3) Differentiate between intrinsic & extrinsic semiconductors.
4) State formula for
i) Capacity of parallel plate condenser
ii) Spherical condenser
iii) Cylindrical condenser
iv) Condensers in parallel

Section – II

Q. 4.A. Attempt any FOUR of the following: 08 Marks
1. What is a fuel cell ?
2. Write two applications of glass based optical fibres.
3. What are insulators ? Give their examples.
4. Define solder.
5. Why does the equivalent conductivity of a weak electrolyte increases with
dilution ?

Q. 4.B. Attempt any TWO of the following: 08 Marks
1. What is cementation ? How is it done ? Explain what is meant by
chromozing.
2. Give reason :
i. Impure metals corrodes faster than pure metal under identical
conditions.
ii. Iron corrodes faster than Aluminium, even though Iron is placed
below Al in the electrical series.
3. Write properties and applications of (a) Teflon, (b) Epoxy resins.

Q. 5. Attempt any THREE of the following: 12 Marks
1. Write briefly about (a) Primary Cells, (b) Secondary Cells.
2. How does fuel cell differ from battery ? What are the advantages and limitations
of fuel cell ?
3. What are the raw materials used in making ceramics ? Write properties
and applications of porcelain.
4. Explain the construction and functioning of a denial cell.

Q. 6. Attempt any THREE of the following: 12 Marks
1. Define metallurgy. What are the important ores of copper ?
2. Describe refining of Aluminium by electrolysis. Name the process.
3. i. Define specific conductivity. How is it related to equivalent conductivity
?
ii. What is buffer solution ? What chemicals can be used to make a buffer of pH
5 and pH 10.
4. Write composition, properties and applications of Babbitt metal.