Q1
MCQ • 1M
Linear Algebra & Vector Calculus
Consider an anti-symumetric tensor P, with the indices i and j running from 1 lo S. The number of independent components of the rensor is (A) 3 (B) 10 (C) 9 (D) 6 D2 The value oi ene integrad fel imfldi, where the comtour e is the unit cirele: (2-2|=1, is (A) 2ri (B) 4 тà (С) пі (D) 0 12 30)
Q2
MCQ • 1M
Linear Algebra & Vector Calculus
The cigenvalues of the matrix (A) 5, 2, -2 12 3 0) 3 10 \cdot 1) are (B) - 5, - 1, -1 for x < 3, (C) 5.1, -1 (D) - 5. 1, 1
Q5
MCQ • 1M
Schrodinger equation & Wave Mechanics
The valence clectrons do not directly determine the following property of a metal. (A) Electrical conductivity (B) Thermal conductivity (C) Shear modulus (D) Metallic lustre 0.6 Consider X-ray diffraction from a crystal with a face-centered-cubic (fcc) lattice. The lattice plane for which there is NO diffraction peak is (A) (2.1,2) (B) (1, 1, 1) (C) (2,0.0) (D) (3, 1. 1) 0.7 The Hall coefficient, Rg, of sodium depends on (A) The effective charge carrier mass and catrier density (B) The charge carrier density and rclaxation lime (C) The charge carrier density only (D) The effective charge carrier mass PH 224 2010 0.8 The Bloch theoremn states that within a crystal, the wavefunction, w(F), of an clectron has the form (A) W(F) =u(r)eti where u(f) is an arbitrary function and & is an arbitrary vector (B) w(F) = u(F)eltir where u(F) is an arbitrary function and & is a reciprocal lattice vector (C) W(7) =u(F)elGi where «(F) =u(P+ À), À is a lattice vector and & is a reciprocal lattice vector (D) W(F) =u(F)elr where u(F) =u(ї + À). À is a lattice vector and & is an arbitrary vector
Q6
MCQ • 1M
Crystal Structure & Lattice Dynamics
Consider X-ray diffraction from a crystal with a face-centered-cubic (fec) lattice. The lattice plane for which there is NO diffraction peak is (A) (2, 1,2) (B) (1,1, 1) (C) (2,0.0) (D) (3, 1, 1) 0.7 The Hall coefficient, Ry, of sodium depends on (A) The effective charge carrier mass and carrier density (B) The charge carrier density and relaxation time (C) The charge carrier density only (D) The effective charge carrier mass PH 2024 3010
Q7
MCQ • 1M
Schrodinger equation & Wave Mechanics
0.9 The Bloch theorem states that within a crystal, the wavefunction, @(F), of an clectron has the form (A) w(r) = «(r)e where «(7) is an arbitrary function and k is an arbitrary vector (B) w(F) = «(F)er where u(F) is an arbitrary function and & is a reciprocal lattice vector (C) y(F) = (F)el where «(F) =u(P+À), À is a lattice vector and G is a reciprocal lattice vector (D) (r) = (r)ed where u(F) = u(i +À). À is a lattice vector and l is an arbitrary vector In an experiment involving a ferromagnetic medium, the following observations were made. Which one of the plots does NOT correctly represent the property of the medium? (I, is the Curie temperature) (B) Spontaneous Magnetization lagnetization (D) Magnetic Susceptibility Specific Heat T.
Q8
MCQ • 1M
Schrodinger equation & Wave Mechanics
The Bloch theorem states that within a crystal, the wavefunction, \psi(\vec{r}), of an electron has the form (A) \psi(\vec{r}) = u(\vec{r})e^{i\vec{k}\cdot\vec{r}} where u(\vec{r}) is an arbitrary function and \vec{k} is an arbitrary vector (B) \psi(\vec{r}) = u(\vec{r})e^{i\vec{G}\cdot\vec{r}} where u(\vec{r}) is an arbitrary function and \vec{G} is a reciprocal lattice vector (C) \psi(\vec{r}) = u(\vec{r})e^{i\vec{G}\cdot\vec{r}} where u(\vec{r}) = u(\vec{r}+\vec{R}), \vec{R} is a lattice vector and \vec{G} is a reciprocal lattice vector (D) \psi(\vec{r}) = u(\vec{r})e^{i\vec{k}\cdot\vec{r}} where u(\vec{r}) = u(\vec{r}+\vec{R}), \vec{R} is a lattice vector and \vec{k} is an arbitrary vector
Q13
MCQ • 1M
Complex analysis
Match the reactions on the left with the associaled interactions on the right. (1) s" → pi +V, (i) Strong (2) 5° →1+1 (ii) Electromagnetic (3) П° +П →П + P (iii) Weak (A) (1, jii), (2, ii), (3, i) (B) (1, i), (2, ii), (3, ii) (C) (1, ii), (2, i), (3, iü) (D) (l, iii), (2, i), (3, ii)
Q22
MCQ • 1M
Statistical Ensembles & Partition Functions
Wincip of the following atoms cunnol exhibit Bose Einsicin condenstion, even in (1)'Il, (В) "Не, (C) "Na,, (D) "K,o PH 3024 2010 "H
Q23
MCQ • 1M
Special theory of relativity
For the set of all Lorentz transformations with velocities along the x-axis, consider the two stutements given below: P: If L is a Lorentz transformation then. L'is also a Lorentz transformation. Q: If 4, and Ly are Lorentz transformations then, 44, is necessarily a Lorentz transformation. Choose the correct option. (A) P is true and Q is false. (B) Both P and Q are true. (C) Both P and Q are false. (D) P is false and Q is true.
Q27
MCQ • 2M
Differential equations
The solution of the differential equation for y(f): ix-y-2codtri) sulject 10 the initial conditions y(0) = 0 and dy =0. is dt liao (A) - cosh(l) +rsinh(t) (B) - sinh(f) + z cosh(f) (C) /cosh(f) (D) /sinh(t) 624 2010 PH 0.28 Given the recurrence relation for the Legendre polynomials (2m +1) * P. (x) = (11+1) Pot, (x) + n PM- (x). which of the following integrals has a non-zero value? (A) j P'P,()P.,(x) ds (B) (xP(XP,(x) dk (oij* leco) ar (DI xr () (7) dx 0.29 Fir, are redimeasional free electron gas, the electronic densily n, and the Fermi energy (A) n = (2mЕ, ) 3 n' (B) n= MEe nh (C) n=-- 2nh mEr (D) ^=- 2%. (mЕ,; ) Tch
Q33
MCQ • 2M
Nuclear Models & Decays
The guark content of E',K*-t and p is indicated: (5) = (uus): (R) =|s): (=) =|ued): (p) =|/und). In the process, n +p→K +&*, considering strong interactions only, which of the following slatements is true? (A) The process is allowed because 45 = 0 (B) The process is allowed because 4/, =0 (C) The process is nol allowed because AS # 0 and A/, # 0 (D) The process is not allowed because the baryon number is violated
Q34
MCQ • 2M
Linear Algebra & Vector Calculus
The three principal moments of inertia of a methanol (CH,OH) molecule have the property I, = 1, =/ and /, # /. The rotational cnergy eigenvalues are (A) E1I+1) +nmg | (8) 1+1) (C) 1) ECA+) Em (2+4)
Q35
MCQ • 2M
Schrodinger equation & Wave Mechanics
A particle of mass m is confined in the poiential V(x) = -mc"x' for x >0, V(x) for x S0. Let the wavefunction of the particle be given by W(0) =-7540+-3543- where y, and yf, are the eigenfunctions of the ground state 0 ** and the first excited state respectively. The expectation value of the energy is (A) 3 n00 (в) 25 ra 10 co) Ln D) "ro 10 FH 8/24
Q36
MCQ • 2M
Electrostatics and Magnetostatics
Match the typical spectra of stable molecules with the corresponding wave-number range 1. Electronic spectra i. 10° cm' and above 2. Rotational spectra ii. 10% -10° cm' 3. Molecular dissociation iii. 10" -10'cm"' (A) 1 - ii, 2 -1, 3 -ilі (В) 1 -ії, 2 - üї, 3-і (C) I - iii, 2 - іi, 3 - і (D) 1 - i, 2-ji, 3 -iji 37 Consider the operations P:f →-7 (parity) and T: -> -1 (time-reversal). For the electri nd magnetic fields E and B, which of the following set of transformations is correct' (A) P:Ê →-E,B → B; 1B) P: Ê→ E.B →B: T: Ё →Ë,B→-B T:Ë→Ё,B→ B (c) P: Ê →-E.B → B. (D) P:È → E.B → - B. T:Ё→-Ё,B→-B T:Ё→-Ё,B-В
Q37
MCQ • 2M
Electrostatics and Magnetostatics
Consider the operations P. 7 → (parity) (parity) and T: ->- (time-reversal. For the electric and magnetic fields E and B, which of the following set of transformations is correct? P:Ê→-Ë,B→ B; P: E→ E,B → B; (A) (B) T:Ẻ →Ë,B→-B T: Ẽ →Ë,B→B (0) P: E→-E, B → B DIP: E- E.B→-B. T: Ë→-Ë,8→ -B T: Ê→-E,B→ B
Q42
MCQ • 2M
Statistical Ensembles & Partition Functions
CO, molecule has the first few energy levels uniformly separated by approximately 2.5 meV. Al a temperature of 300 K, the ratio of the number of molecules in the 4'"' excited slate to the number in the 200 excited siale is about (A) 0.5 (B) 0.6 (C) 0.8 (D) 0.9 243 Whieh apy: he callowine yee oet syaxwell edaios is eneret? (- inicrmal energy. CA) T -(2V) and p-(95), (8) V -(**), and T=lasl (0) P--(38) mar-(38), (D) p=-(%), and s = (3A).
Q44
MCQ • 2M
Electrostatics and Magnetostatics
For a spin-s particle, in the eigen basis of 5%. S, the expoctation value (sm|S; (sm) is (A) - Nfs(s+1)-m'} (B) s°(s(s+1)-2m*) 2 (C) 1°{s(s+1)-mi*} (D) n'm PH 11/24 2010 0.45 A paricle is placed in a region with the porenial V(x)==xx'- 3'*", where k.A>0. (A) r=D and x=ê are points or stable equiliorium (B) x = 0 is a point of stable cquilibrium and *=* is a point of unstable equilibrium (C) x =0 and x =. - are points of unstable equilibrium (D) There are no points of stable or únstable equilibrium 0.46 A a" meson at rest decays into Iwo pholons, which move along the x- axis. They are both detecied simultaneously after a time, t = 10 s. In an inertial frame moving with a velocity V = 0.6c in the direction of one of the photons, the lime interval belween the lwo detections is (A) 15 s (B) 0s (C) 10s (D) 20 s 0.47 A particle of mass m is confined in an infinite porential well: if O< x<L. V(x)=1 otherwise. I is sulbiected 1o a perurtbing porential V,(+) - V,sin(2Zt) Vợ) within the well. Lel E"" and E'" be the corrections to the ground state energy in the first and second order in V, Vр(х) respectively. Which of the following are true? L (A) E"' = 0; E3<0 (В) Е"> 0; E:=0 (C) E"'= 0; E*" depends on the sign of Vo (D) E'" <0: E3<0 Common Data Questions Common Data for Questions 48 and 49: In the presence of a weak magnetic field, alomic hydrogen undergoes the transition: 3Py →'Sy, by emision of radiation.
Q51
MCQ • 2M
Bose-Einstein and Fermi-Dirac statistics
The pressure of the photon gas is (A) P' (k9T)" 15 tỉc (8) 7 4) (C) T (KT)" 45 h'c3 (D) 2 (K,T)% 45 h'c' PH 13/24 2010 PH Linked Answer Questions Stalement for Linked Answer Questions 52 and 53: Consider the propagation of electromagnetic waves in a linear, homogeneous and isotropic material medium with electric permittivitye, and magnetic permeabilily i.
Q64
MCQ • 2M
Complex analysis
. S skilied workers can build a wall in 20 days; 8 semi-skilled workers can build a wall in 25 days: ) unskilled workers can build a wall in 30 days. If a team has 2 skilled, & semi-skilled an unskilled workers, how long will it take to build the wall (A) 20 days (B) 18 days (C) 16 days (D) 15 days Q,65. Comme digis 2, 2. 3, 3, 3,4, 4, 4, 4 how many distince a digit numbers gireater than 300 can be (A) 50 (B) 51 (C) 52 (D) 54 END OF THE QUESTION PAPER PH 1624 2010 PH Space for Rough Work PH 2010 PH Space for Rough Work PH 1{24 2010 PH Space for Rough Work FH 1924 2010 PS1 Space for Rough Work 2024 2010 Space for Rough Work PH 21/24 2010 Space for Rough Work PH 22724 2010 PH Space for Rough Work 171 2,224 2010 PH Space for Rough Work SFAI 24724