
	Trending ▼ ICSE CBSE 10th ISC CBSE 12th CTET GATE UGC NET Vestibulares ResFinder

GATE 2015 : Physics

16 pages, 55 questions, 3 questions with responses, 3 total responses,

	gate	+Fave Message
	Profile Timeline Uploads Q & A

Home > gate >

Instantly get Model Answers to questions on this ResPaper. Try now!
NEW ResPaper Exclusive!

Formatting page ...

GATE 2015 PHYSICS-PH Q. 1 Q. 25 carry one mark each. Q.1 A satellite is moving in a circular orbit around the Earth. If T, V and E are its average kinetic, average potential and total energies, respectively, then which one of the following options is correct? (A) (C) (B) (D) The Pauli matrices for three spin- particles are 1 , 2 , and 3 , respectively. The dimension of Q.2 is __________ the Hilbert space required to define an operator O 1 2 3 Q.3 The mean kinetic energy of a nucleon in a nucleus of atomic weight A varies as An, where n is ______________ (upto two decimal places) Q.4 Let L and p be the angular and linear momentum operators, respectively, for a particle. The commutator [ L x , p y ] gives (A) i p z Q.5 (B) 0 (C) i p x (D) i p z The decay e is forbidden, because it violates (A) momentum and lepton number conservations (B) baryon and lepton number conservations (C) angular momentum conservation (D) lepton number conservation Q.6 B , where B An operator for a spin- particle is given by A are matrices and is a constant. The eigenvalues of A (A) B / 2 PH (B) B (C) 0, B B y ), denotes Pauli (x 2 (D ) 0, B 1/14 GATE 2015 Q.7 , In an inertial frame S, two events A and B take place at c t A 0, rA 0 and ctB 0, rB 2 y PHYSICS-PH respectively. The times at which these events take place in a frame S moving with a velocity with respect to S are given by 0.6 c y (A) (C) c t A 0 ; c t B 3 / 2 (B) c t A 0; c tB 3 / 2 (D) c t A 0; c tB 0 c t A 0; c tB 1/ 2 Q.8 Given that the magnetic flux through the closed loop PQRSP is A dl R value of A dl 1 along PQR, the R P . If along PSR is P Q P R S (A) 1 Q.9 (B) 1 (C) 1 (D) 1 If f ( x ) e x and g ( x ) x e x , then 2 2 (A) f and g are differentiable everywhere (B) f is differentiable everywhere but g is not (C) g is differentiable everywhere but f is not (D) g is discontinuous at x = 0 Q.10 In Bose-Einstein condensates, the particles (A) have strong interparticle attraction (B) condense in real space (C) have overlapping wavefuntions (D) have large and positive chemical potential PH 2/14 GATE 2015 Q.11 PHYSICS-PH Consider a system of N non-interacting spin- particles, each having a magnetic moment , is in . If E is the total energy of the system, the number of accessible a magnetic field B B z microstates is given by (A) (C) Q.12 N! 1 E 1 E ! N N ! 2 B 2 B E 1 E 1 ! N N ! 2 B 2 B E N B ! (B) E N B ! (D) N! E N B ! For a black body radiation in a cavity, photons are created and annihilated freely as a result of emission and absorption by the walls of the cavity. This is because (A) the chemical potential of the photons is zero (B) photons obey Pauli exclusion principle (C) photons are spin-1 particles (D) the entropy of the photons is very large Q.13 Consider w f z u x, y iv x, y to be an analytic function in a domain D. Which one of the following options is NOT correct? (A) u x, y satisfies Laplace equation in D (B) v x, y satisfies Laplace equation in D f z dz is dependent on the choice of the contour between z z2 (C) 1 and z 2 in D (D) f z can be Taylor expanded in D z1 Q.14 PH The value of is _________________ (upto one decimal place) 3/14 GATE 2015 Q.15 PHYSICS-PH Which one of the following DOES NOT represent an exclusive OR operation for inputs A and B ? (A) (C) Q.16 (B) (D) Consider a complex function f(z) = (A) f(z) has simple poles at . Which one of the following statements is correct? and (B) f(z) has a second order pole at (C) f(z) has infinite number of second order poles (D) f(z) has all simple poles Q.17 In the given circuit, the voltage across the source resistor is 1 V. The drain voltage (in V) is _______ 25 V 5 k 2 M 500 Q.18 A point charge is placed between two semi-infinite conducting plates which are inclined at an angle of 30o with respect to each other. The number of image charges is ______________ Q.19 A beam of X-ray of intensity I0 is incident normally on a metal sheet of thickness 2 mm. The intensity of the transmitted beam is 0.025I0. The linear absorption coefficient of the metal sheet (in m-1) is _______________ (upto one decimal place) PH 4/14 GATE 2015 Q.20 Q.21 PHYSICS-PH The lattice parameters a, b, c of an orthorhombic crystal are related by a 2b 3c . In units of a, the interplanar separation between the (110) planes is __________ (upto three decimal places) In a Hall effect experiment, the Hall voltage for an intrinsic semiconductor is negative. This is because (symbols carry usual meaning) (A) n p Q.22 (C) e > h (B) n > p The space between two plates of a capacitor carrying charges +Q and Q is filled with two different dielectric materials, as shown in the figure. Across the interface of the two dielectric materials, which one of the following statements is correct? +Q (A) and are continuous -Q (B) (C) is continuous and is discontinuous (D) Q.23 Q.24 (D) is continuous and is disconitnuous and are discontinuous The energy dependence of the density of states for a two dimensional non-relativistic electron gas is given by, g E CE n , where C is constant. The value of n is ______________ The dispersion relation for phonons in a one dimensional monatomic Bravais lattice with lattice spacing a and consisting of ions of masses M is given by, k 2C 1 cos ka , where is M the frequency of oscillation, k is the wavevector and C is the spring constant. For the long wavelength modes a , the ratio of the phase velocity to the group velocity is _________ PH 5/14 GATE 2015 Q.25 PHYSICS-PH F1 K exp( r 2 / R2 )r Four forces are given below in Cartesian and spherical polar coordinates. (i) (ii) (iii) y3 z ) F2 K ( x 3 y y3 y ) F3 K ( x3 x / r) (iv) F4 K ( where K is a constant. Identify the correct option. (A) (iii) and (iv) are conservative but (i) and (ii) are not (B) (i) and (ii) are conservative but (iii) and (iv) are not (C) (ii) and (iii) are conservative but (i) and (iv) are not (D) (i) and (iii) are conservative but (ii) and (iv) are not Q. 26 Q. 55 carry two marks each. Q.26 2 2 Consider a system of eight non-interacting, identical quantum particles of spin-3/2 in a one dimensional box of length L. The minimum excitation energy of the system, in units of 2mL2 is ___________ Q.27 The excitation wavelength of laser in a Raman effect experiment is 546 nm. If the Stokes line is observed at 552 nm, then the wavenumber of the anti-Stokes line (in cm-1) is ___________ Q.28 The binding energy per molecule of NaCl (lattice parameter is 0.563 nm) is 7.95 eV. The repulsive term of the potential is of the form K , where K is a constant. The value of the Madelung constant r9 is ____________ (upto three decimal places) ; (Electron charge e = Q.29 Given that the Fermi energy of gold is 5.54 eV, the number density of electrons (upto one decimal place) is ____________ (Mass of electron = Q.30 PH ) ) . At 300 K, the Fermi and The band gap of an intrinsic semiconductor is level with respect to the edge of the valence band (in eV) is at ________ (upto three decimal places) 6/14 GATE 2015 Q.31 Q.32 PHYSICS-PH The number of permitted transitions from 2P3/2 2S1/2 in the presence of a weak magnetic field is _________________ Which one of the following represents the electron occupancy for a superconductor in its normal and superconducting states? (A) (B) Normal state Superconducting state f(E) E E E Superconducting state f(E) f(E) f(E) E (D) (C) Normal state Superconducting state Normal state f(E) f(E) E PH Normal state Superconducting state f(E) E f(E) E E 7/14 GATE 2015 Q.33 PHYSICS-PH A charge q is distributed uniformly over a sphere, with a positive charge q at its center in (i). Also in (ii), a charge q is distributed uniformly over an ellipsoid with a positive charge q at its center. With respect to the origin of the coordinate system, which one of the following statements is correct? X X Z Y Z Y (i) (A) The dipole moment is non-zero in (i) but zero in (ii) (C) The dipole moment is zero in (i) but non-zero in (ii) (D) PH The dipole moment is zero in both (i) and (ii) (B) (ii) The dipole moment is non-zero in both (i) and (ii) 8/14 GATE 2015 Q.34 PHYSICS-PH Consider the circuit shown in the figure, where RC = 1. For an input signal Vi shown below, choose the correct Vo from the options: (A) (B) vo 1 1 2 3 t -1 (D) (C) Q.35 A long solenoid is embedded in a conducting medium and is insulated from the medium. If the current through the solenoid is increased at a constant rate, the induced current in the medium as a function of the radial distance r from the axis of the solenoid is proportional to (A) inside the solenoid and outside (C) inside the solenoid and PH outside (B) (D) inside the solenoid and outside inside the solenoid and outside 9/14 GATE 2015 Q.36 PHYSICS-PH In the simple current source shown in the figure, Q1 and Q2 are identical transistors with current gain and The current Io (in mA) is ___________ (upto two decimal places) Q.37 Match the phrases in Group I and Group II and identify the correct option. Group I Group II (P) Electron spin resonance (ESR) (Q) Nuclear magnetic resonance (NMR) (R) Transition between vibrational states of a molecule (S) Electronic transition (i) radio frequency (ii) visible range frequency (iii) microwave frequency (iv) far-infrared range (A) (P-i), (Q-ii), (R-iii), (S-iv) (C) (P-iii), (Q-iv), (R-i), (S-ii) Q.38 (B) (P-ii), (Q-i), (R-iv), (S-iii) (D) (P-iii), (Q-i), (R-iv), (S-ii) Consider the motion of the Sun with respect to the rotation of the Earth about its axis. If Fc and FCo denote the centrifugal and the Coriolis forces, respectively, acting on the Sun, then (A) Fc is radially outward and FCo = Fc (B) Fc is radially inward and FCo = 2 Fc (C) Fc is radially outward and FCo = 2 Fc (D) Fc is radially outward and FCo = 2 Fc Q.39 PH In a rigid-rotator of mass M, if the energy of the first excited state is 1 meV, then the fourth excited state energy (in meV) is _____________ 10/14 GATE 2015 Q.40 PHYSICS-PH iy E0 exp i kz t after passing through an optical element emerges as A plane wave x iy E0 exp i kz t , where k and are the wavevector and the angular frequency, x respectively. The optical element is a (A) quarter wave plate (C) polarizer Q.41 (B) half wave plate (D) Faraday rotator (A) (C) Q.42 The Lagrangian for a particle of mass m at a position r moving with a velocity v is given by m L v 2 C r .v V r , where V(r) is a potential and C is a constant. If pc is the canonical 2 momentum, then its Hamiltonian is given by 2 1 pc C r V r 2m pc2 V r 2m (B) (D) 2 1 pc C r V r 2m 1 2 pc C 2 r 2 V r 2m The Hamiltonian for a system of two particles of masses m1 and m2 at r1 and r2 having velocities C 1 1 2 r1 r2 , where C is a constant. Which 2z v1 and v2 is given by H m1v12 m2v2 2 2 r1 r2 one of the following statements is correct? (A) The total energy and total momentum are conserved (B) Only the total energy is conserved (C) The total energy and the z - component of the total angular momentum are conserved (D) The total energy and total angular momentum are conserved Q.43 A particle of mass 0.01 kg falls freely in the earth s gravitational field with an initial velocity v (0) 10 ms-1. If the air exerts a frictional force of the form, f kv , then for , the velocity (in ms-1) at time t = 0.2 s is ________ (upto two decimal places) (use PH and e = 2.72) 11/14 GATE 2015 Q.44 PHYSICS-PH In the nuclear shell model, the potential is modeled as V r 1 m 2 r 2 L S , 0 . The 2 13 correct spin - parity and isospin assignments for the ground state of C is 1 1 ; 2 2 (A) 3 1 ; (D) 2 2 3 1 ; (C) 2 2 Q.45 1 1 ; 2 2 (B) A particle is confined in a box of length L as shown below. V0 L2 If the potential V0 is treated as a perturbation, including the first order correction, the ground state energy is 2 2 V0 2mL2 2 2 2 V0 (D) E 2mL2 2 2 2 V0 2mL2 2 2 V0 (C) E 2mL2 4 (B) E (A) E Q.46 i 1 2 0 e 1 at t = 0 where 0 and 1 are the ground and the first excited 2 Suppose a linear harmonic oscillator of frequency and mass m is in the state states, respectively. The value of x in the units of Q.47 at t = 0 is ___________ m A particle with rest mass M is at rest and decays into two particles of equal rest masses 3 M 10 which move along the z axis. Their velocities are given by (A) v1 v2 0.8c z (C) v1 v2 0.6c z PH (B) v1 v2 0.8c z ; (D) v1 0.6c z v2 0.8c z 12/14 GATE 2015 Q.48 PHYSICS-PH In the given circuit, if the open loop gain A = 105, the feedback configuration and the closed loop gain are vi + _ vo 9 k 1 k (A) series-shunt, (C) series-shunt, Q.49 9 RL (B) series-series, (D) shunt-shunt, 10 10 10 A function y( z) satisfies the ordinary differential equation y 1 m2 y 2 y 0 , where z z m 0,1, 2,3,... . Consider the four statements P, Q, R, S as given below. m m P: z and z are linearly independent solutions for all values of m m m Q: z and z are linearly independent solutions for all values of m>0 R: ln z and 1 are linearly independent solutions for m = 0 m S: z and ln z are linearly independent solutions for all values of m The correct option for the combination of valid statements is (A) P, R and S only Q.50 (B) P and R only (D) R and S only aVE 3 2 S Nk B ln N 52 , where E is the total energy, a is a constant and k B is the Boltzmann constant. The chemical potential of the system at a temperature T is given by The entropy of a gas containing N particles enclosed in a volume V is given by aVE 3 2 (A) k BT ln 5 2 N aVE 3 2 (C) k BT ln 3 2 N PH (C) Q and R only 5 2 5 2 aVE 3 2 (B) k BT ln 5 2 N aVE 3 2 (D) k BT ln 3 2 N 3 2 3 2 13/14 GATE 2015 Q.51 PHYSICS-PH 1 2 1 2 1 p1 p2 m 2 r12 r2 2 k 1 2 , 2m 2m 2 where 1 and 2 denote the corresponding Pauli matrices, 0.1eV and k 0.2 eV . If the Let the Hamiltonian for two spin- particles of equal masses m, momenta p1 and p2 and positions r1 and r2 be H ground state has net spin zero, then the energy (in eV) is ___________ Q.52 The average energy U of a one dimensional quantum oscillator of frequency a heat bath at temperature T is given by (A) U (C) U Q.53 1 1 coth 2 2 (B) U 1 1 tanh 2 2 (D) U and in contact with 1 1 sinh 2 2 1 1 cosh 2 2 A monochromatic plane wave (wavelength = 600 nm) E0 exp i kz t is incident normally on a diffraction grating giving rise to a plane wave E1 exp i k1 r t 1 diffraction. Here E1 E 0 and k 1 k 1 x 2 in the first order of 3 . The period (in m) of the diffraction z 2 grating is _____________ (upto one decimal place) Q.54 2i / . The Fourier transform of sin 2 (A) 2 (C) sin 2 Q.55 1 for t 0 and its Fourier transform is given by 1 for t 0 The Heaviside function is defined as H (t ) 1 H (t 1 / 2) H (t 1 / 2) is 2 cos 2 (B) 2 (D) 0 152 1 The atomic masses of 152 63 Eu , 62 Sm , 1 H and neutron are 151.921749, 151.919756, 1.007825 and 1.008665 in atomic mass units (amu), respectively. Using the above information, the Q-value of the 152 -3 reaction 152 63 Eu n 62 Sm p is __________ 10 amu (upto three decimal places) END OF THE QUESTION PAPER PH 14/14 Graduate Aptitude Test in Engineering Notations : Question Paper Name: Number of Questions: Total Marks: PH: PHYSICS 1st Feb Shift2 65 100.0 Wrong answer for MCQ will result in negative marks, (-1/3) for 1 mark Questions and (-2/3) for 2 marks Questions. Number of Questions: Section Marks: 10 15.0 Q.1 to Q.5 carry 1 mark each & Q.6 to Q.10 carry 2 marks each. Question Number : 1 Question Type : MCQ Options : Question Number : 2 Question Type : MCQ Options : Question Number : 3 Question Type : MCQ Options : Question Number : 4 Question Type : MCQ Options : Question Number : 5 Question Type : MCQ Options : Question Number : 6 Question Type : MCQ

Formatting page ...

Top Contributors
to this ResPaper
(answers/comments)

Bibi Mohanan Mohanan
(1)

Nilesh Chauhan
(1)

Sipun Mohanty
(1)

Formatting page ...

Tags : India, GATE Exam Question Papers, Free Online Solutions, Answers, Answer Key, Graduate Aptitude Test in Engineering, IIT, IISc, GATE Exam Syllabus, GATE Study Material, GATE Exam Pattern, gate exam papers, gate question papers 2016, 2015, 2014, 2013, 2012, 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000, 1999, 1998, 1997, 1996, 1995, 1994, 1993, 1992, 1991, past gate papers, gate papers with answers, gate entrance exam engineering, gate previous years papers, gate old papers, gpat.

gate chat

Horizontal lines at:
Guest Horizontal lines at:
AutoRM Data:
Box geometries: