This document contains the complete and authentic B.Tech (Semester II) PHYSICS Theory Examination Question Paper for the academic session 2018–19, Subject Code KAS201, Total Marks 100, Time 3 Hours.
It is structured to test a student's understanding of engineering physics, including modern physics, optics, lasers, electromagnetic theory, relativity, and quantum mechanics.
The examination is divided into three major sections, each designed to evaluate conceptual clarity, analytical skills, numerical problem-solving, and the ability to apply physics principles to practical scenarios.
SECTION A — Short Conceptual Questions (2 × 10 = 20 Marks)
This section contains 10 brief questions covering fundamental physics concepts.
Students must demonstrate basic understanding of:
Negative outcome of Michelson–Morley experiment
Concept of length contraction in relativity
Inertial vs non-inertial frames of reference
Nature and properties of massless particles
Definition of displacement current
Meaning of Poynting vector and Poynting theorem
Assumptions in Planck’s quantum hypothesis
Necessity of extended sources in interference
Formation of Newton’s rings
Definition of dispersive power of diffraction grating
These questions test the student’s foundational knowledge across modern physics, optics, and electromagnetics.
SECTION B — Analytical & Descriptive Questions (Any 3 × 10 = 30 Marks)
This section evaluates deeper understanding through detailed explanations, derivations, and numerical calculations.
Topics include:
1. Special Theory of Relativity
Derivation of time dilation
Numerical question involving moving clock losing 30s in 24 hours
2. Interference in Thin Films
Conditions for maxima/minima
Complementary nature of reflected vs transmitted light patterns
3. LASER Physics
Working of 3-level and 4-level laser systems
Advantages of 4-level LASER over 3-level
4. Optical Fibers
Definition & classification
Calculations of:
Numerical aperture (NA)
Acceptance angle
Critical angle
5. Electromagnetic Theory
Continuity equation + significance
Calculation of E-field & B-field at a distance from a lamp
This section emphasizes problem-solving and application of physics laws.
SECTION C — Long Answer / Application-Based Questions (40 Marks)
Each subsection contains two questions, from which the student attempts one.
Part 3 — Relativity / Diffraction
Derivation of Einstein’s mass–energy relation, E = mc²
Numerical question on relativistic mass, momentum, energy
OR
Fraunhofer diffraction at a single slit + intensity distribution
Part 4 — EM Waves / LASER
Proof that electromagnetic waves are transverse
Numerical problems on conduction & displacement current
OR
Ruby Laser construction & energy calculation
Part 5 — Quantum Theory / Maxwell’s Equations
Derivation of Planck’s radiation law
Applications: Wien’s law and Rayleigh-Jeans law
OR
Maxwell’s equations & modification of Ampere’s law
Part 6 — EM Radiation Pressure / Compton Effect
Derivation of radiation momentum and pressure
OR
Full derivation of Compton shift with numerical calculation
Part 7 — Quantum Mechanics / Grating
Derivation of Schrödinger’s equations
OR
Diffraction grating, missing orders & angular separation calculation
These questions test advanced reasoning, detailed derivations, and numerical analysis.
SAMPLE QUESTIONS FROM THE PAPER
To illustrate the depth of the exam, here are two sample questions included in the document:
Example 1 (Section A):
What is displacement current?
— Tests basic electromagnetic theory.
Example 2 (Section C):
Deduce Einstein’s mass–energy relation E = mc².
— Tests deep conceptual understanding of relativity.
Overall Coverage of the Question Paper
This question paper thoroughly covers core areas of physics required for engineering students:
Modern Physics & Relativity
Length contraction, time dilation
Mass–energy equivalence
Michelson–Morley experiment
Electromagnetic Theory
Maxwell’s equations
Displacement current
EM wave properties (E & B field calculations)
Optics
Newton’s rings
Diffraction (Fraunhofer)
Interference in thin films
Grating spectra
Quantum Mechanics
Schrödinger equations
Planck’s radiation law
Compton effect
Laser & Fiber Optics
Ruby laser, 3-level & 4-level lasers
Optical fibers: NA, critical angle, acceptance angle
Wave Physics
Radiation pressure
Momentum of EM waves
The paper checks both theoretical understanding and numerical competence, making it a complete assessment tool for first-year engineering physics.
