PhD
entrance examination – 2023 January
Subject:
Physics
1. To
determine the value of lagrangian, we assume
A) Kinetic
energy B) Potential energy C) Both A and B D) None of these
2. In the inverse piezoelectric effect, ______ waves are
produced.
A) Electromagnetic B)
Infrasonic C) Ultrasonic D) Micro
3. A thermodynamic process in which pressure remains constant is called
A) Isobaric B) Isothermal C) Isotropic D) Isocyclic
4. How many ways can the Hamilton’s equation be derived?
A) 1 B) 2 C) 3 D) 4
5. The equation of the plane that is tangent to the surface xyz=8 at point (1,2,4) is
A) 4x + 2y+ z =12 B) x + 2y+ 4z =12 C) x + 4y+ 2z =12 D) x + y+ z =7
6. The number of
independent ways in which a mechanical system can move without violating any
constraint is called
A) Degrees of
freedom B)
Number of freedoms
C)
Generalized coordinates D)
Wavefunctions
7. The role of
He in He-Ne laser is
A) He is an
active medium B) Population inversion takes place
in He
C) Stimulated
emission takes place in He D) He atoms helps in exciting Ne
atoms
8. Which one of the following has highest intermodal
dispersion?
A) Step index single mode B)
Step index multimode
C) Graded index multimode D) All have same intermodal
dispersion
9. Which of the following is described by the concept of numerical aperture in an optical fiber?
A) Light scattering B) Light collection C) Light deviation D) Light polarization
10. An electron and a proton are
accelerated through same potential. The ratio of de-Broglie wavelength 
is
A) 1 B)
C)
D)
11. In canonical transformation, the set of variables obey
A) Pythagorean theorem B) Hamilton’s equations
C) Newton’s laws D) Law of thermodynamics
12. The Andromeda galaxy is which of the following types of galaxies?
A) Elliptical B) Spiral C) Barred-spiral D) Irregular
13. Which one of the following is a structure of CNT?
A) Armchair B) Zig-zag C) Chiral D) All of these
14. Orientation polarization occurs
A) In all dielectrics B) In polar dielectrics
C) In non-polar dielectrics D) In ionic dielectrics
15. Which of the following waves/rays are produced by nuclear changes in the atom?
A) Infrared rays B) Ultrasonic waves C) Gamma rays D) X-rays
16. Which of the
following are the properties of superconductors?
A) They are diamagnetic in
nature B) They
have zero resistivity
C) They have infinite conductivity D) All of the above
17. A proton and an alpha
particle are accelerated through the same potential difference V. The
wavelengths associated with these two particles will be in the ratio
A) 1:2 B) 2:1 C)
4:1 D) None of these
18. If the momentum of an object increases by 20%, its kinetic energy will increase by,
A) 66% B) 77% C) 44% D) 55 %
19. The region of electromagnetic spectrum for nuclear magnetic resonance is
A) Microwave B) Infrared C) Radio frequency D) UV rays
20. When electrons are trapped in the crystal lattice in place of anion vacancy, the defect in the crystal is known as
A) Non-stochiometric defect B) Stochiometric defect
C) F-centre D) Frenkel defect
21. Which one of the following common devices works on the basis of the principle of mutual induction?
A) LED B) Photodiode C) Transformer D) Transistor
22. A ferroelectric crystal loses spontaneous polarization at
A) Transition temperature B) Fermi temperature
C) Curie temperature D) Debye temperature
23. If the function neither satisfied even parity & odd parity, then function is said to be
A) Indefinite parity B) Symmetric potential
C) Degenerate state D) None of these
24. An astronaut at rest has a heart rate of 65 beats/min. When the astronaut’s spaceship moves at a speed of 0.6c, her heart rate in beats/min as measured by an earth observer will be:
A) 26 B) 52 C) 74 D) 104
25. In which direction, the recoil electron in Compton scattering has the maximum kinetic energy?
A) 00 B) 900 C) 1800 D) 2700
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