UPSC IFS 2023 Physics Paper I Question Paper PDF

Central Government Jobs Other Jobs 2023

  • Year 2023
  • Conducted By UPSC
  • Questions 8
  • Maximum Marks 200
  • Duration Three Hours
  • Languages English

Exam Details

Detail Information
Examination Indian Forest Service (Main) Examination
Year 2023
Conducting Body UPSC
Paper Physics Paper - I
Subject Physics
Duration Three Hours
Maximum Marks 200
Number of Questions 8
Question Type Descriptive / Subjective

This is the Physics Paper I from the Indian Forest Service (Main) Examination conducted by UPSC in 2023. The paper consists of 8 questions, of which 5 are to be attempted. Questions 1 and 5 are compulsory, and candidates must select at least one question from each of the two sections (A and B) from the remaining six questions. This paper is crucial for candidates aspiring to join the Indian Forest Service, providing a clear understanding of the exam's scope and difficulty level in Physics.

Major Topics Covered

  • Physics
  • Physical Constants
  • Indian Forest Service (Main) Examination
  • Physics Paper - I
  • UPSC
  • 2023 question paper
  • previous year paper
  • PDF download

Why This Paper is Important

  • Useful for Indian Forest Service (Main) Examination preparation
  • Helps understand the latest exam pattern
  • Useful for practice and self-assessment
  • Covers frequently asked General Studies topics
  • Helpful for analysing question trends

Related Resources

  • Indian Forest Service (Main) Examination 2023 Physics Paper II
  • Indian Forest Service (Main) Examination 2022 Physics Paper I
  • Civil Services Examination 2023 Physics Optional Paper
  • Indian Forest Service (Main) Examination 2023 Physics Paper I Answer Key
  • UPSC IFS 2023 Physics Paper I Solutions
  • Indian Forest Service Physics Syllabus
  • UPSC Main Examination Physics Syllabus
  • Indian Forest Service Main Examination Pattern

Instructions

  • There are EIGHT questions in all, out of which FIVE are to be attempted.
  • Out of the remaining SIX questions, THREE are to be attempted selecting at least ONE question from each of the two Sections A and B.
  • Attempts of questions shall be counted in sequential order.
  • Unless struck off, attempt of a question shall be counted even if attempted partly.
  • Any page or portion of the page left blank in the Question-cum-Answer Booklet must be clearly struck off.
  • The number of marks carried by a question/part is indicated against it.
  • Unless otherwise mentioned, symbols and notations have their usual standard meanings.
  • Assume suitable data, if necessary and indicate the same clearly.
  • Neat sketches may be drawn, wherever required.
  • Answers must be written in ENGLISH only.
  • Useful Constants: = 1.602 \times 10^{-19} C Electron charge (e) = 9.109 \times 10^{-31} kg Electron rest mass (m_e) = 1.672 \times 10^{-27} kg Proton mass (m_n) = 8.854 \times 10^{-12} farad/m Vacuum permittivity (\epsilon_0) = 4\pi \times 10^{-7} T m/A Vacuum permeability (\mu_0) Velocity of light in free space (c) = 3 \times 10^8 m/s = 1.380 \times 10^{-23} \text{ J/K} Boltzmann constant (k) = 1.602 \times 10^{-19} J Electronvolt (eV) = 6.626 \times 10^{-34}J s Planck constant (h) = 5.67 \times 10^{-8} W m-2 K-4 Stefan constant (σ) = 6.022 \times 10^{26} kmol-1 Avogadro number (N) 8.31\times10^{3} J kmol-1 K-1 Gas constant (R) 2.718 exp(1)

Questions (page 2)

Section A

Q1. A particle of mass m moves under the action of a central force whose potential is V(r) = Kmr4 (K > 0). Calculate the kinetic energy for which the orbit will be a circle of radius R, about the origin. What are the coordinates of the centre of mass of the system of masses shown in the figure? Calculate the velocity of a particle having kinetic energy four times the rest mass energy. Explain with proper examples the techniques of obtaining interference by 'division of wavefront' and 'division of amplitude'. A length of 25 cm of a solution containing 50 gm of solute per litre causes a rotation of the plane of polarization of light by 5°. Find the rotation of the plane of polarization by a length of 75 cm of the solution containing 100 gm of solute per litre.

Section A

Q2. A hoop is rolling down on an inclined plane without slipping. Find its velocity at the bottom of the inclined plane. Calculate the inertia tensor for a rigid body consisting of three particles of masses 3 gm, 1 gm, 2 gm located at (1, -1, 2) cm, (1, 0, 2) cm, (-2, 1, 0) cm respectively. Define Einstein's coefficients A and B for spontaneous and stimulated emissions, and write the relation between them. If the Einstein's coefficient of spontaneous emission is 107/s, determine the Einstein's coefficients for the stimulated emission for the emission wavelength of 5800 Å.

Question paper preview

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Indian Forest Service (Main) Examination 2023 Physics Paper I question paper page 1 instructions scan PDF download. UPSC IFS 2023 Physics Paper I instructions and useful constants.
Page 2
Indian Forest Service (Main) Examination 2023 Physics Paper I question paper page 1 instructions scan PDF download. UPSC IFS 2023 Physics Paper I instructions and useful constants.

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Frequently asked questions

What is the name of the exam?

The exam is the Indian Forest Service (Main) Examination.

Which year is this question paper from?

This question paper is from the year 2023.

Who conducts the Indian Forest Service Examination?

The Indian Forest Service Examination is conducted by UPSC (Union Public Service Commission).

What is the subject of this paper?

This paper is Physics Paper - I.

What is the paper code?

The paper code is BJKE-U-PHY/46.

How many questions are there in total?

There are 8 questions in total.

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