This is a Question Papers of Mumbai University for B.Sc.IT Student of Semester - I [Electronic and Communication Technology] (Revised Course). [Year - April / 2014] . . .Solution Set of this Paper is Coming soon..

1. E l e c t r o n i c s a n d C o m m u n i c a t i o n s T e c h n o l o g y
Q u e s t i o n P a p e r ( A p r i l – 2 0 1 4 ) [ R e v i s e d C o u r s e ]
1 | Page
M u m b a i B . S c . I T S t u d y
F a c e b o o k | T w i t t e r | I n s t a g r a m | G o o g l e + | Y o u T u b e
– Kamal T.
Time: 3 Hours Total Marks: 100
N.B.: (1) All Questions from 1 to 7 are Compulsory.
(2) Figure To right indicate the marks.
Q.1 Attempt Both The Question: (10 Marks)
(A) Explain how a transistor can be used as a switch. (5)
(B) What is digital communication? With suitable diagram explain ASK in detail. (5)
Q.2 Attempt Any Three From The Following: (15 Marks)
(A) With the help of neat circuit diagram and proper input waveform’s, explain the
working of bridge rectifier using pn junction code.
(5)
(B) What is Zener Diode? Discuss its application in Voltage Regulation. (5)
(C) Draw the output characteristics of a transistor connected in CE Configuration and
explain the various regions of operation.
(5)
(D) With the help of energy band diagrams, explain the concept of Conductors, Insulators
and Semiconductors.
(5)
Q.3 Attempt Any Three From The Following: (15 Marks)
(A) What do you mean by Darlington pair? (5)
(B) Write a short note on DC Amplifiers. (5)
(C) Derive the expression for voltage gain of a Multistage Amplifier having ‘n’ amplifiers
cascaded.
(5)
(D) Draw the Frequency Response of a Single Stage Amplifier and explain. (5)
Q.4 Attempt Any Three From The Following: (15 Marks)
(A) What do you mean by feedback? Explain Negative and Positive feedback in brief. (5)
(B) With the help of circuit diagram explain a stable multivibrator using 555 timer. (5)
(C) With the help of Circuit Diagram explain RC Phase Shift Oscillator. (5)
(D) Calculate the time period of a stable multivibrator, if 𝑅 𝐴 = 4.7𝑘Ω, 𝑅 𝐵 = 2.2𝑘Ω, and
𝐶 = 0.33𝜇𝐹.
(5)
Q.5 Attempt Any Three From The Following: (15 Marks)
(A) Explain a Typical Radio Transmitter System using block diagram. (5)
(B) Define Amplitude Modulation and Modulation Index for Amplitude Modulation. (5)
(C) What is the need for Modulation in Communication System? (5)
(D) Derive the equation for total power used in Transmitting Amplitude Modulated Wave. (5)

2. E l e c t r o n i c s a n d C o m m u n i c a t i o n s T e c h n o l o g y
Q u e s t i o n P a p e r ( A p r i l – 2 0 1 4 ) [ R e v i s e d C o u r s e ]
2 | Page
M u m b a i B . S c . I T S t u d y
F a c e b o o k | T w i t t e r | I n s t a g r a m | G o o g l e + | Y o u T u b e
– Kamal T.
Q.6 Attempt Any Three From The Following: (15 Marks)
(A) Differentiate between AM and FM system. (5)
(B) What do you mean by sampling? State and explain Sampling Theorem. (5)
(C) Write a note on Pulse Amplitude Modulation (PAM). (5)
(D) Write a note on Pulse Width Modulation (PWM). (5)
Q.7 Attempt Any Three From The Following: (15 Marks)
(A) Describe the construction of an Optical Fibers. (5)
(B) With the help of diagram explain Total Internal Reflection. (5)
(C) Write a short note on LASER. (5)
(D) Explain the following terms:
(i) Attenuation
(ii) Dispersion
(iii) Optical Dtectorss.
(5)