No. of Printed Pages: 4 IBME-021 I
B.Tech. MECHANICAL ENGINEERING
(COMPUTER INTEGRATED
MANUFACTURING) I
B.Tech. (AEROSPACE ENGINEERING) (BTAE)

Term-End Examination 01..7 December, 2016
BME-021 PRINCIPLES OF ELECTRICAL AND ELECTRONICS SCIENCE
Time hours Maximum Marks: 70
Note: Answer any five questions. Use of scientific calculator is allowed. Assume any data, if missing.

1. A coil is wound uniformly with 300 turns over a steel ring of relative permeability 900 having a mean diameter of 20 em. The steel ring is made of a bar having circular cross-section of diameter 2 cm. If the coil has a resistance of 50 ohm and is connected to a 250 V d.c. supply, calculate the m.m.f. of the coil,

(ii) field intensity in the ring,

(iii) reluctance of the magnetic path, and

(iv) total flux.

Distinguish between conductors, semiconductors and insulators. 6

Two coils with negligible resistance and of self-inductance of 0.2 H and 0.1 H respectively are connected in series. If their
mutual inductance is 0.1 calculate the effective inductance of the combination. 2

2. State and explain KVL and KCL laws. 6

Find the currents I1,I2 and I3 by using superposition theorem in the following network: 6
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State the maximum power transfer theorem.

3. Three capacitors, each of 150 micro are connected in delta to a 400 3-phase, 50 Hz supply. Calculate the line current. What will be the capacitance of each of the three capacitors such that when connected in star across the same supply, the line current remains same? 6
Derive the e.m.f. equation of a single-phase transformer. 6

(c) Why is cooling of a transformer essential? 2

4. Why is a starter necessary for starting of large 3-phase induction motor? Describe star-delta starter with a neat sketch. 6

The series resonant circuit is often called as acceptor circuit and parallel circuit as the rejector circuit. Explain. 6

A 3-phase induction motor having 8 poles runs on a 50 Hz supply. If it operates at full load at 720 r.p.m., calculate the slip. 2

5. What is a Zener diode? Draw and explain its characteristics. 6

Describe briefly how a p-n junction is formed with p-type and n-type semiconductors. How is a depletion layer formed? 6

What are the characteristics of an ideal operational amplifier? 2

6. Draw the architecture of 8085 MPU and briefly explain the various sub-units. 6

What is Transistor biasing Explain any one method of biasing. 6

Give the symbol and truth table of NAND logic gate. 2

7. Show how the amplifier is used as an inverting amplifier, and

(ii) a non-inverting amplifier.

Also give the gain equations. 3 3=6 Explain the De Morgan's theorem. Also calculate (AB (AB D). 3 3=6· What are semi-conductor memories? 2