Organization : Union Public Service Commission
Exam : Indian Forest Service Main Exam
Subject : Physics
Document Type : Sample Question Papers
Location : India
Year : 2015
Website : https://www.upsc.gov.in/
Download Model/Sample Question Paper Physics I 2015 : https://www.pdfquestion.in/uploads/8386PhysicsPaperI.pdf
Download Model/Sample Question Paper Physics II 2015 : https://www.pdfquestion.in/uploads/8386PhysicsII.pdf
UPSC Indian Forest Service Physics Question Paper
Download Question Paper of Indian Forest Service Main Exam Physics Sample Question Paper is now available in the official website of Union Public Service Commission.
Related : UPSC Indian Forest Service Main Exam Geology Sample Question Paper : www.pdfquestion.in/8390.html
Question Paper Specific Instructions
Please read each of the following instructions carefully before attempting questions :
** There are EIGHT questions in all, out of which FIVE are to be attempted.
** Questions no. 1 and 5 are compulsory. Out of the remaining SDX 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.
** All questions carry equal marks. The number of marks carried by a question/part is indicated against it.
** Answers must be written in ENGLISH only.
** Neat sketches may be drawn, wherever required
Model Questions
Section—A :
1. Answer all of the following :
a. The Lagrangian for a particle has the form Obtain its form in plane polar coordinates and then get expression for the Hamiltonian using appropriate transformation.
b. Discuss that the motion of a particle in a central field gets restricted to a plane provided its angular momentum is nonzero. What will happen if the angular momentum is zero?
c. Find the velocity and momentum of a particle having rest mass m0 and kinetic energy equal to two times of its rest mass energy.
d. In Young’s double-slit experiment, a thin mica sheet (refractive index =1-5} is introduced in the path of one of the beams. If the central fringe gets shifted by 0-2 cm, calculate the thickness of the mica sheet. Assume separation between the two slits (d) and between slit and source (D) as d = 0 – 1 cm and D = 50 cm.
e. Explain physically why dispersion is diminished in multimode parabolic-index number than in step-index number
f. Solve Euler’s equation of motion for a rigid body to show that the torque-free motion of a spherical top is a uniform rotation about an axis fixed in space.
Section—B :
Answer all of the following :
a. Verify whether the electric potential V =15x2yz—5ysz satis?es Laplace’s equation or not.
b. In a simple AC circuit involving only a resistor R=SOQ and a voltage source V, ?nd the linear frequency of the generator if V = 0-5 Vm (Vm is peak e.m.f.) at time t=:’r;—Os (assuming V=O at 13:0)
c. Which of the Maxwell equations imply that there are no magnetic monopoles? Explain how the equations would get modified if magnetic monopoles’ would exist
d. Discuss the consequence following from Joule’s free expansion experiments in the context of the internal energy of an ideal gas
e. Derive an expression for the total number of particles N in an ideal Bose gas at any temperature T. Hence, obtain the relation
f. Prove that the work done on the charges by the electromagnetic force is equal to decrease in energy stored in the field, less the energy that flowed out through the surface. Explain what you mean by the Poynting vector. 20+5
1. Write notes on the following : 8X5=40
(a) Signi?cances of conjugation in Paramecium
(b) Adaptive diversity in polychaetes based on habitat
(c) Effects of torsion in gastropods and its signi?cance
(d) Air sacs in pigeon and their functions
(e) Adaptations of aquatic mammals
2. (a) J‘Evolution of metazoan is the differentiation of cells to perform different functions.” Justify this in relation to the cellular organization of hydrozoans. 15
(b) Discuss the af?nities of Onychophora and suggest a suitable place for this in the animal kingdom. 15
(c) Explain how the structure and life history of Fasciola hepatica are suitable for parasitic mode of life. 10
3. (a) Discuss the signi?cance of echinoderrn larvae. 15
(b) Describe the adaptive devices of tropical freshwater ?shes to live in marshes and swamps. 15
(c) Describe the types of skull in Reptilia with neat labelled sketch. 10
4. (a) Describe the functions of ovarian hormones. 10
(b) Compare the aortic arches of reptiles with birds with neat sketch. 15
(c) Describe different types of jaw suspension in vertebrates with neat sketch. 15
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