Physics
GATE PH topic:physical-sciences PYQs
Build your understanding with focused practice from past exam papers.
Questions 431–440 of 650. Imported answers require independent review unless marked reviewed.
Question 31
Open questionPHMCQ2 marksNeeds review
Consider the Lagrangian
, where
,
and
are constants. If
and
are the momenta conjugate to the coordinates
and
respectively, then the Hamiltonian isYour answerChoose one option.
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Which one of the following matrices does NOT represent a proper rotation in a plane?
Your answerChoose one option.
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A uniform magnetic field
exists in an inertial frame
. A perfect conducting sphere moves with a constant velocity
with respect to this inertial frame. The rest frame of the sphere is
(see figure). The electric and magnetic fields in
and
are related as
The induced surface charge density on the sphere (to the lowest order in
) in the frame
is 
Your answerChoose one option.
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A charge
moving with uniform speed enters a cylindrical region in free space at
and exits the region at
(see figure). Which one of the following options best describes the time dependence of the total electric flux
, through the entire surface of the cylinder? 
Your answerChoose one option.
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Consider a one-dimensional non-magnetic crystal with one atom per unit cell. Assume that the valence electrons (i) do not interact with each other and (ii) interact weakly with the ions. If
is the number of valence electrons per unit cell, then at 0 K,Your answerChoose one option.
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According to the Fermi gas model of the nucleus, the nucleons move in a spherical volume of radius
, where
is the mass number and
is an empirical constant with the dimensions of length. The Fermi energy of the nucleus
is proportional toYour answerChoose one option.
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Consider a two dimensional crystal with 3 atoms in the basis. The number of allowed optical branches (
) and acoustic branches (
) due to the lattice vibrations areYour answerChoose one option.
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The internal energy
of a system is given by
, where
is a constant of appropriate dimensions;
and
denote the volume and entropy, respectively. Which of the following gives the correct equation of state of the system?Your answerChoose one option.
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The potential energy of a particle of mass
is given by
The angular frequency of small oscillations of the particle about
isYour answerChoose one option.
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The radial wave function of a particle in a central potential is given by
, where
is the normalization constant and
is positive constant of suitable dimensions. If
is the most probable distance of the particle from the force center, the value of
is _____.Log in to check the answer
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