B.Sc. (Part – I) (Semester – II),Solapur University Question Paper,ELECTRONICS (Old) Basic Electronics (Paper – III),



Solapur University Question Paper
B.Sc. (Part – I) (Semester – II) Examination, 2014
ELECTRONICS (Old)
Basic Electronics (Paper – III)
Day and Date : Tuesday, 20-5-2014 Max. Marks : 50
Time : 11.00 a.m. to 1.00 p.m.
Instructions : 1) All questions are compulsory.
2) Figures to the right indicate full marks.
3) Use of log table and calculator is allowed.
4) Draw neat and labelled diagram wherever necessary.
1. Select correct alternative for the following : 10
i) A pentavalent impurity has ____________ valence electrons.
a) 3 b) 4
c) 5 d) 6
ii) A bridge full wave rectifier uses ____________ diodes.
a) 4 b) 2
c) 1 d) none
iii) In depletion region contains only
a) holes b) free electrons
c) ions d) none of these
iv) The purpose of a filter is to
a) minimise variations in ac input signal
b) supress harmonics in rectified output
c) remove ripples from the rectified output
d) stabilize dc output voltage
v) The β of a transistor is 99, then the value of α is
a) 9.9 b) 0.99
c) 99 d) 100
P.T.O.
Seat
No.
SLR-C – 43 -2- 
vi) The phase difference between the input and output voltage in a common base
configuration is
a) 180° b) 90°
c) 270° d) 0°
vii) The operating point on a load line is also called the
a) cutoff point b) saturation point
c) quiescent point d) none of these
viii) A JFET is a ____________ driven device.
a) voltage
b) current
c) both voltage and current
d) none of these
ix) Barrier potential of PN junction decreases by ___________ per degree rise in
temperature.
a) 2 mV b) 2 V
c) 20 mV d) 20 V
x) In a n channel JFET, the charge carriers are
a) electrons
b) holes
c) both electrons and holes
d) ions
2. Answer any five of the following : 10
i) Draw a symbol of zener diode and photo diode with labels.
ii) Explain the effect of temperature on extrensic semiconductor.
iii) Draw a circuit diagram of half wave rectifier with input and output wave forms.
iv) A typical transistor has β = 99. Calculate the value of α .
v) State different types of transistor biasing.
vi) Why MOSFET is also called as an insulated gate FET ?
 -3- SLR-C – 43
3. A) Answer any two of the following : 6
i) Define transconductance of FET. Find the value of transconductance if
μ = 80 and rd = 400 kΩ .
ii) Write a short note on N-type semiconductor.
iii) Write a short note on dc load line.
B) Write a short note on photodiode. 4
4. Answer any two of the following : 10
i) Show that the maximum efficiency of full wave rectifier is 81.2%.
ii) With the help of suitable circuit diagram, explain IV characteristics of PN
junction diode.
iii) Describe transistor action in detail.
5. Answer any two of the following : 10
i) Explain temperature compensation using single diode.
ii) Explain output characteristics of transistor in CE configuration.
iii) Write a short note on capacitor filter.
_______________

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