Communication Engineering (BEC401) - AKTU Question Paper 2025-26
B.Tech · Semester 4 · Free PDF Download
This is the official AKTU Communication Engineering Previous Year Question Paper for B.Tech Semester 4, academic session 2025-26. Published by Dr. A.P.J. Abdul Kalam Technical University (AKTU/UPTU), Lucknow. Free PDF download — no login required.
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Questions Asked in 2025-26
Communication Engineering (BEC401) — complete question paper · 70 marks · 3 Hours
- aState the need of modulation in communication system
- bCalculate the transmission efficiency of an AM signal with 100% modulation
- cState Carson’s rule for the bandwidth of an FM signal
- dDefine white noise and its power spectral density
- eWhat do you mean by time division multiplexing?
- fExplain the term granular noise in delta modulation
- gBriefly explain the concept of quadrature amplitude modulation
- aWhat do you mean by amplitude modulation (AM)? Derive the mathematical expression AM-DSB/FC. Also provide the graphical representation for modulation index less than one
- bExplain the Armstrong method of FM generation with a detailed block diagram and discuss the spectral characteristics of FM signals using Bessel functions
- cExplain the concepts of pre-emphasis and de-emphasis in FM and derive how they improve SNR
- dExplain the concept of companding in PCM systems and its importance
- eDraw and explain the block diagram for a binary frequency shift keying transmitter and receiver
- aThe antenna current of an AM broadcast transmitter, modulated to a depth of 30% by an audio sine wave is 10A. It increases to 12A as a result of sinusoidal modulation by another audio sine wave. What is the modulation index due to second wave?
- bDraw the block diagram of a complete communication system and explain the function of each block. 1 K2 (SEM. IV) THEORY EXAMINATION 2025-26 COMMUNICATION ENGINEERING
- aDemonstrate the generation of FM with the help of PM and vice-versa
- bExplain the demodulation of an FM wave using a phase locked loop with a functional block diagram
- aState the various types of noises encountered in a communication system
- bDerive the expression for the signal to noise ratio and figure of merit for a double side band suppressed carrier system
- aDiscuss the process of quantization in PCM. Prove that for a PCM signal, the signal to quantization noise ratio in dB is 1.8 + 6n approximately, where n is the number of bits per sample
- bExplain Delta Modulation. Discuss the causes of slope overload distortion and how to minimize it. Derive mathematical expression of Smin
- aExplain amplitude shift keying using waveforms. Draw the block diagram for its generation and coherent detection
- bDescribe the minimum shift keying scheme. Prove that the phase of a minimum shift keying signal remains continuous at bit transitions
Question text is extracted from the official AKTU question paper PDF above. Hindi translations are omitted — every question is printed in English in the original paper. Last verified: 2026-08-23.
Repeated Questions — BEC401
Questions that appeared in more than one session, found by comparing 3 years of Communication Engineering papers (2023-24, 2024-25, 2025-26)
State the need of modulation in communication system
Appeared in: 2023-24 · 2024-25 · 2025-26
State Carson’s rule for the bandwidth of an FM signal
Appeared in: 2024-25 · 2025-26
The antenna current of an AM broadcast transmitter, modulated to a depth of 30% by an audio sine wave is 10A. It increases to 12A as a result of sinusoidal modulation by another audio sine wave. What is the modulation index due to second wave?
Appeared in: 2023-24 · 2025-26
State the various types of noises encountered in a communication system
Appeared in: 2023-24 · 2025-26
Derive the expression for the signal to noise ratio and figure of merit for a double side band suppressed carrier system
Appeared in: 2023-24 · 2025-26
Communication Engineering — Other Year Papers
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