About this previous year paper
This is a complete AKTU Engineering Physics (KAS101) question paper for B.Tech 1st semester, designed according to the official 100-mark university pattern. The paper covers all the fundamental topics of modern physics, optics, electromagnetic theory, quantum mechanics, lasers, fiber optics, and special relativity.
The paper is divided into three structured sections – A, B, and C, ensuring comprehensive coverage of theory, numericals, conceptual understanding, and derivations.
This question paper is ideal for semester exam preparation, viva practice, assignments, unit revision, and self-study.
SECTION A – Short Questions (10 × 2 = 20 Marks)
This section checks understanding of core physics concepts:
Postulates of special theory of relativity
Why nothing can move faster than light
Modification of Ampere’s law & displacement current
Depth of penetration in EM waves
de-Broglie wavelength of photon
Physical significance of wave function ψ
Why two sources cannot be coherent
Resolving power of optical instruments
Spontaneous vs stimulated emission (laser action)
Principle of optical fiber
These are essential 2-mark concepts frequently repeated in exams.
SECTION B – Descriptive Questions (Attempt Any 3 × 10 = 30 Marks)
This section includes derivations, explanations, and quantum concepts:
Special Relativity
Relativistic velocity addition theorem
Consistency with Einstein’s postulates
Maxwell’s Equations
Integral & differential forms
Physical meaning of each equation
Speed of EM waves c=1μ0ϵ0c = \frac{1}{\sqrt{\mu_0 \epsilon_0}}c=μ0ϵ01
Quantum Mechanics
Time-independent and time-dependent Schrödinger equations
Fraunhofer Diffraction (Single Slit)
Formation of maxima and minima
Relative intensity distribution
Optical Fibers
Structure, types (step-index, graded-index, multimode, single-mode)
Advantages & disadvantages
This section strengthens conceptual clarity and derivation skills.
SECTION C – Long Questions (Attempt Any 2 from Each Set) (5 × 2 = 10 Marks per section)
Q3 – Relativity
Choose any 2:
Length contraction derivation
Apparent volume of a moving cube
Variation of mass with velocity
These are the core formulas of special relativity.
Q4 – Electromagnetic Waves
Choose any 2:
Poynting vector & Poynting theorem
Coulomb’s law derived from Maxwell’s first equation
Magnitude of solar Poynting vector using Sun’s power and radius
These questions test EM wave theory and vector calculus.
Q5 – Quantum Mechanics
Choose any 2:
Particle in a 1D box: eigenvalues and normalized wave function
Compton effect and Compton shift derivation
Proof that the given function represents a stationary state
This section covers the most important quantum physics topics.
Q6 – Interference & Diffraction
Choose any 2:
Newton's rings formation + formula for dark ring diameters
Thin wedge film → calculate angle of wedge
Overlapping of spectral lines in diffraction grating
Optics questions common in AKTU exams.
Q7 – Lasers & Fiber Optics
Choose any 2:
Construction & working of Ruby Laser
Population ratio in He-Ne laser
Numerical aperture, acceptance angle, critical angle of a fiber
These questions cover laser physics & fiber communication.