B.TechSemester 42025-26Signal SystemBEC403

Signal System (BEC403) - AKTU Question Paper 2025-26

B.Tech · Semester 4 · Free PDF Download

This is the official AKTU Signal System 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.

Course:B.Tech

Semester:Semester 4

Session:2025-26

University:AKTU / UPTU

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Questions Asked in 2025-26

Signal System (BEC403) — complete question paper · 70 marks · 3 Hours

Section AAttempt all questions in brief. 02 x 7 = 14

a
Distinguish between deterministic and random signals with a suitable example for each
b
Determine if the signal 2( ) ( ) tx t e u t −= is an energy or power signal
c
Define a stable LTI system using the BIBO criterion
d
State the Dirichlet conditions for the existence of the Fourier series
e
Write the time shifting property of the Laplace transform
f
Define the region of convergence (ROC) and its significance in Z - transforms
g
Briefly explain the concept of aliasing in sampling

Section BAttempt any three of the following: 07 x 3 = 21

a
Define even and odd signals. Determine the even and odd components of the signal
b
An LTI system is characterized by the differential equation: ( ) ( )5 6 ( ) ( )d y t dy t y t x tdt dt + + = Determine the step response ()st of the system, assuming initial conditions are zero
c
Using the Fourier transform, find the convolution of 1( ) ( ) atx t e u t −= and 2( ) ( ) btx t e u t −=
d
Find the Z -transform and the ROC of the sequence ( ) (1/ 3) ( ) (1/ 2) ( 1)nnx n u n u n= + − −
e
State and prove the sampling theorem for low-pass signals

Section CAttempt any one part of the following: 07 x 1 = 07

a
Check the system 2( ) ( ) 2y t x t=+ for linearity, causality, and time - invariance
b
Determine the fundamental period of the signal ( ) cos(10 ) sin(20 )x t t t =+ , if it is periodic. 1 K3 (SEM. IV) THEORY EXAMINATION 2025-26 SIGNAL SYSTEM
a
Compute the convolution integral of ( ) ( )x t u t= and
b
Find the impulse response ()ht of an LTI system that produces the output 24( ) ( ) ( ) tty t e e u t−−=− when the input is
a
Find the inverse Laplace transform of sXs ss += ++ for the ROC
b
State and prove Parseval’s theorem for the continuous-time Fourier transform
a
Determine the Z-transform and sketch the ROC for 0( ) sin( ) ( )nx n a n u n =
b
Use the partial fraction method to find the inverse Z -transform of zHz zz= −−
a
Explain the reconstruction of a signal from its samples using an ideal interpolation filter
b
A signal 2( ) (100 ) 3 (60 )x t sinc t sinc t =+ is to be sampled. (i) Identify the maximum frequency component , (ii) Calculate the Nyquist sampling rate and Nyquist sampling interval

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.