Veer Narmad South Gujarat University 2010 B.E Basic Electronics - 2 ( Sem3 )( Chemical ) - Question Paper

RN-6125

B. E. - II (Sem. Ill) (Chemical) Examination May/June - 2010 Basic Electronics

Time : 3 Hours]    [Total Marks : 100

Instructions :

(1)

(2)    Attempt all questions.

(3)    Figures to the right indicate full marks.

(4)    Assume suitable data wherever necessary and specify your assumption clearly.

1 (a) Answer the following :    10

(i)    A bridge type rectifier has _ diodes.

(ii)    A pentavalent impurity has _valence

electrons.

(iii)    Define :

(a)    PIV

(b)    Filters

(c)    Cut in voltage

(iv)    At room temperature, an intrinsic semiconductor acts as _.

(v)    A zener diode is used as a _.

(vi)    The ripple factor of a half wave rectifier is_.

(vii)    The relation between B and D is _.

(viii)    In a transistor, signal is transferred from a _circuit.

(b)    Explain half wave rectifier and derive equation    6 for its efficiency.

(c)    Define filter and compare various filters.    4

2 (a) Explain with the help of neat diagram transistor    8

working as an amplifier.

(b) Describe with the characteristics, the voltage    7

stabilization of zener diode.

OR

2    (a) Define biasing of transistor. List the various    8

methods of biasing and explain voltage divider biasing.

(b) Describe the working of following filters    7

(i)    Capacitive filter

(ii)    k filter.

3    Write short notes on : (any three)    15

(i)    Comparison of CE, CB, CC configuration of transistor.

(ii)    Classification of amplifiers

(iii)    Uni-junction transistor

(iv)    Push pull amplifier.

SECTION-II

4    (a) (i) An astable multivibrator__1

(a)    Gives one output pulse for every two input pulse.

(b)    Give a timed output pulse for trigger input.

(c)    Gives a train of output pulses for trigger input.

(d)    Gives four output pulses for single input pulse.

(ii)    The electrons emitted by a thermionic emitter 1 are called_.

(a)    Free electron

(b)    Loose electron

(c)    Thermionic electron

(d)    Bound electron

(iii)    In signal generators energy is converted from 2

simple _ source into _ energy at some

specific frequency. (iv) Define work function. 2 (v) What is full form of LED? 2 (vi) What is deflection sensitivity of CRT? 2 (i) List various devices used for measurement of 4 temperature. (ii) What is field emission? 3 (iii) Give merits and demerits of multimeter. 3

(a)    What is secondary Emission? Explain with    7 labelled diagram.

OR

(a) Determine frequency of oscillation and feedback

Given = 0.001 Micro Faeade, C₂ = 0.01 Micro faeade L = 15 Micro henry

(b) Explain Barkhausen criteria with neat block diagram. 7

6 Any three :    15

(i)    Explain frequency measurement using CRO.

(ii)    What is Photo Electric emission? Explain with diagram.

(iii)    Write about Thermionic Emitter.

(iv)    Write a note on photodiode with characteristics.

RN-6125]    3    [ 200 ]

Attachment: veer-narmad-south-gujarat-university-2010-b-e-28385-1.pdf

Earning:   Approval pending.