About this previous year paper
This document contains the official AKTU B.Tech 1st Semester 2020–21 Theory Examination question paper for Engineering Physics (KAS101T). It is a full 100-mark, 3-hour examination paper that follows the complete AKTU pattern with Section A, Section B, and Section C. This paper is extremely useful for students preparing for semester exams, sessionals, and internal assessments.
Engineering Physics is a core subject that develops a strong foundation in relativity, electromagnetic theory, quantum mechanics, wave optics, lasers, fibre optics, and matter waves. This official question paper helps students understand the exact exam format, marking scheme, and types of numerical and theoretical questions asked by AKTU.
Detailed Breakdown of the Question Paper
SECTION A – 10 Short Questions (10 × 2 = 20 Marks)
This section includes 10 very short questions, each worth 2 marks, covering fundamental concepts such as:
Einstein’s postulates of Special Relativity
Photon momentum calculation
Displacement current
Why magnetic monopoles do not exist
Wien’s displacement law & Rayleigh-Jeans law
Nature of matter waves
Why independent sources do not show interference
Rayleigh criterion & resolving power
Spontaneous vs stimulated emission
Components of an optical fibre (with diagram)
These questions are ideal for quick revision and fast scoring.
SECTION B – 3 Medium-Length Questions (3 × 10 = 30 Marks)
Students must attempt any 3 out of 5 questions. Topics include:
Lorentz transformations & invariance of space-time interval
Conduction current density & displacement current density calculations
Lowest energy states in an infinite potential well
Thin film interference (soap bubble)
Optical fibre attenuation and power calculation
This section involves numerical problems and conceptual derivations, helping students practice mid-level difficulty questions.
SECTION C – 5 Long Answer Questions (5 × 10 = 50 Marks)
Each question has two alternatives; students must attempt one part from each. These include:
Question 3 – Relativity
Time dilation with derivation & experimental evidence
OR
Mass–energy relation and relativistic kinetic energy
Question 4 – Electromagnetic Theory
Maxwell’s equations in free space + EM wave propagation
OR
Poynting theorem with derivation & significance
Question 5 – Quantum Mechanics
Wave function and derivation of time-independent Schrödinger equation
OR
Compton effect + formula for Compton shift
Question 6 – Wave Optics
Newton’s rings formation + proof for diameters of dark rings
OR
Diffraction due to plane grating
Question 7 – Lasers & Fibre Optics
Construction, working & applications of He-Ne laser
OR
Acceptance angle & numerical aperture derivations
This section prepares students for high-scoring theoretical answers.
Why This Question Paper is Important for Students
This question paper is valuable because it:
Matches the actual AKTU exam pattern
Covers all high-weightage chapters from the syllabus
Includes numerical, derivation-based, and diagram-based questions
Helps build conceptual clarity in core physics topics
Acts as a perfect last-moment revision tool
Shows commonly repeated question formats
Improves confidence for both theory and problem-solving
It is especially helpful for students of CSE, IT, ECE, EE, ME, CE, EI, EN and all first-year engineering programs.