Physics
GATE PH kind:question PYQs
Build your understanding with focused practice from past exam papers.
Questions 481–490 of 650. Imported answers require independent review unless marked reviewed.
Question 16
Open questionPHMCQ1 markNeeds review
An infinitely long thin cylindrical shell has its axis coinciding with the
-axis. It carries a surface charge density
, where
is the polar angle and
is a constant. The magnitude of the electric field inside the cylinder isYour answerChoose one option.
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Open questionPHNAT1 markNeeds review
Consider a three-dimensional crystal of
inert gas atoms. The total energy is given by
, where
,
, and
is the nearest neighbor distance between two atoms. The two constants,
and
, have the dimensions of energy and length, respectively. The equilibrium separation between two nearest neighbor atoms in units of
(rounded off to two decimal places) isLog in to check the answer
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Open questionPHNAT1 markNeeds review
The energy-vector (
-
) dispersion relation for a particle in two dimensions is
, where
is a constant. If its density of states
is proportional to
then the value of
isLog in to check the answer
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Open questionPHNAT1 markNeeds review
A circular loop made of a thin wire has radius 2 cm and resistance 2
. It is placed perpendicular to a uniform magnetic field of magnitude
Tesla. At time
the field starts decaying as
, where
s. The total charge that passes through a cross section of the wire during the decay is
. The value of
in
C (rounded off to two decimal places) isLog in to check the answer
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Open questionPHNAT1 markNeeds review
The electric field of an electromagnetic wave in vacuum is given by
The wave is reflected from the
surface. If the pressure exerted on the surface is
, the value of
(rounded off to one decimal place) isLog in to check the answer
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Open questionPHNAT1 markNeeds review
The Hamiltonian for a quantum harmonic oscillator of mass
in three dimensions is
where
is the angular frequency. The expectation value of
in the first excited state of the oscillator in units of
(rounded off to one decimal place) isLog in to check the answer
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Open questionPHNAT1 markNeeds review
The Hamiltonian for a particle of mass
is
where
and
are the generalized coordinate and momentum, respectively,
is time and
is a constant. For the initial condition,
and
at
,
. The value of
isLog in to check the answer
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Open questionPHNAT1 markNeeds review
At temperature
Kelvin (K), the value of the Fermi function at an energy 0.5 eV above the Fermi energy is 0.01. Then,
, to the nearest integer, is
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Open questionPHNAT1 markNeeds review
Let
,
represent two possible states of a two-level quantum system. The state obtained by the incoherent superposition of
and
is given by a density matrix that is defined as
. If
and
, the matrix element
(rounded off to one decimal place) isLog in to check the answer
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Open questionPHNAT1 markNeeds review
A conventional type-I superconductor has a critical temperature of 4.7 K at zero magnetic field and a critical magnetic field of 0.3 Tesla at 0 K. The critical field in Tesla at 2 K (rounded off to three decimal places) is
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