B.TechSemester 12025-26Engineering PhysicsBAS101

Engineering Physics (BAS101) - AKTU Question Paper 2025-26

B.Tech · Semester 1 · Free PDF Download

This is the official AKTU Engineering Physics Previous Year Question Paper for B.Tech Semester 1, 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 1

Session:2025-26

University:AKTU / UPTU

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Questions Asked in 2025-26

Engineering Physics (BAS101) — complete question paper · 70 marks · 3 Hours

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

a
Calculate the energy difference between the ground state and the first excited state for an electron in a one-dimensional rigid box of length 10−10 m
b
State the physical significance of displacement current in Maxwell’s equations
c
For a plane transmission grating with 5000 lines/cm, determine the highest order of spectrum observable with light of 6000 Å
d
Differentiate between spontaneous emission and stimulated emission of radiation
e
Explain the role of population inversion in laser action
f
State any two important properties of quantum dots and mention their significance
g
What is meant by persistent current?

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

a
Describe the Davisson–Germer experiment with a neat diagram. How does this experiment verify de Broglie’s hypothesis of matter waves?
b
Explain the concept of Poynting vector and discuss its physical meaning
c
Discuss the formation of interference fringes due to a thin wedge -shaped film as seen by normally reflected sodium light. Derive an expression for the fringe width
d
What is the difference between step index fibre and graded index fibre? Explain with suitable diagrams. Also discuss the mechanism of light propagation in both types of optical fibres
e
Explain Type-I and Type-II superconductors

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

a
Explain the concept of black body radiation and state the main features of Planck’s radiation law
b
Write and solve the Schrödinger wave equation for a particle in a one- dimensional infinite potential box and obtain its eigenfunctions and eigenvalues
a
Deduce the equation for the propagation of plane electromagnetic waves in the free space. Show that the electric and magnetic vectors are normal to each other and to the direction of propagation of the wave
b
Explain the principle of conservation of electric charge and discuss its importance in electromagnetic theory
a
Explain and obtain the condition of absent spectra in plane transmission grating. If the width d of the opaque space (ruling) is equal to the width e of the transparent space, which orders will be absent? Which if d = 2e?
b
Discuss Fraunhofer Diffraction of light at a double slit and obtain the conditions for diffraction and interference maxima and minima
a
Describe the construction and working principle of a He-Ne with the help of a suitable diagram
b
What are the sources of attenuation of signal in an optical fibre? Explain
a
What is the critical magnetic field? How does it vary with temperature? Critical temperature of superconductor when no magnetic field is applied is 𝑇𝑐. Find the temperature at which the critical field becomes half of its value at 0 K
b
Explain the method of preparation of Nanomaterials (i) Sol- Gel method and (ii) Chemical Vapour Deposition methods in detail

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.