RTU Kota B.Tech 1st Year Engineering Physics Sem-I Question Paper 2025

RTU Engineering Physics Sem-I 2025 Paper Review

Preparing for the Rajasthan Technical University B.Tech Engineering Physics exam requires a strong understanding of fundamental physical laws and mathematical derivations. The Sem-I 2025 paper tests your core theoretical knowledge and your ability to solve numerical problems based on complex formulas. Reviewing this paper shows you exactly how examiners structure the questions and allocate marks among the syllabus modules. This preparation allows you to approach your semester exam with confidence.

Understanding the Exam Pattern

The RTU theory examination is a three hour paper worth 70 marks. The paper consists of three distinct sections.

• Part A: This section contains ten compulsory questions worth two marks each. You must write short answers under 30 words.
• Part B: You will find seven questions here. You must answer five of them. Each question is worth four marks. Your answers should be around 100 words.
• Part C: This section offers five major questions. You need to answer three. Each question carries ten marks. These require detailed mathematical derivations, ray diagrams, or multi step numerical solutions.

Core Topics Evaluated in the Paper

The Sem-I 2025 question paper covers several critical modules. Focus your study time on these specific areas to maximize your score.

Wave Optics

This is a highly mathematical section. You must know the theory of interference and diffraction. Practice the complete derivation for the diameter of dark and bright rings in Newton's rings experiment. The paper frequently includes numerical problems asking you to calculate the wavelength of light using a Michelson interferometer. You must also study Fraunhofer diffraction at a single slit and N-slits (diffraction grating). Be ready to define and calculate the resolving power of a grating and Rayleigh's criterion of resolution.

Quantum Mechanics

Examiners consistently ask for the derivation of the Compton shift. You must understand the de Broglie hypothesis and Heisenberg's uncertainty principle. The core of this module is the Schrodinger wave equation. Practice deriving both the time dependent and time independent forms. You need to explain the physical significance of the wave function. Expect a major ten mark question requiring you to find the eigen values and eigen functions for a particle trapped in a one dimensional rigid box.

Coherence and Lasers

You must differentiate between spatial and temporal coherence. Study the principles of spontaneous and stimulated emission. Practice deriving the relation between Einstein's A and B coefficients. You need to know the basic components of a laser system, including the active medium, pumping source, and optical resonator. Prepare the construction, working principle, and energy level diagrams for both the Ruby laser and the Helium Neon (He-Ne) laser.

Optical Fibers

This module features simple numerical problems. You need to explain the principle of total internal reflection. Practice the derivations for acceptance angle and numerical aperture. Study the structural and functional differences between step index and graded index optical fibers. You must also explain the causes of signal loss, specifically attenuation and dispersion, in optical communication.

Electrodynamics

This section tests your knowledge of Maxwell's equations. You must define displacement current. Practice writing all four Maxwell's equations in both integral and differential forms. Examiners frequently ask for the derivation of the Poynting vector and the Poynting theorem. You need to understand the propagation of electromagnetic waves in free space and dielectric media.

Answer Writing Strategy for High Marks

RTU evaluators look for specific mathematical steps, clear definitions, and neat diagrams in your answer booklet. Use a blue pen for your main text and a black pen for headings and final formulas.

In Part A, answer directly. If the question asks for the definition of numerical aperture, write the exact formula and define the terms. Do not write lengthy introductions. Keep answers factual and precise.

In Part B, provide a brief explanation accompanied by the relevant formula or small graph. When asked about the differences between step index and graded index fibers, use a comparison format. List four specific differences to make your answers easy to scan.

In Part C, detail is essential. When deriving the radius of Newton's rings or the Schrodinger wave equation, write down your initial assumptions clearly. Draw a large, neat, labeled diagram using a pencil. Break your answer into clear headings. Write out every single mathematical step. The university marking system awards step by step marks even if your final numerical answer has a minor calculation error. Enclose your final derived formula in a rectangular box to make it stand out to the evaluator.

Time Management During the Exam

Allocate 20 minutes to Part A. Spend 40 minutes on Part B. Reserve the remaining 120 minutes for the three long answer questions in Part C. Deriving Maxwell's equations or solving particle in a box problems takes significant time. This structure gives you 40 minutes per major question, allowing you to complete your derivations and double check your mathematical signs. Use the final 10 minutes to verify your numerical answers, check units like nanometers or electron volts, and ensure all variables are properly defined in your derivations.