GATE PH Solid State Physics PYQs & Answers

Questions 1–10 of 65. Imported answers require independent review unless marked reviewed.

Consider a metal-superconductor junction connected to a dc voltage

. At

, where

is the superconductor’s transition temperature, the current

versus

behavior of this junction is shown schematically in the figure below. If the superconducting energy gap is

meV. The value of

(rounded off to one decimal place) is ____

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For the energy dispersion of an electron in a one-dimensional solid

, the ratio of the effective mass of the electron in the solid to the free electron mass (

) at

. Taking

and

, the value of

(rounded off to two decimal place) is ____

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The dispersion (

) of the conduction band (CB) and valence band (VB) for a semiconductor are shown schematically in the figure. Considering the possibility of an electron making a transition from the bottom of the CB to the top of the VB, which of the following options is/are correct?

Your answerSelect all correct options. You can choose more than one.

The transition is forbidden.

A photon can be emitted with an energy exactly equal to

A photon can be emitted with an energy less than

A phonon can be created with crystal momentum

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Copper has an electron number density of

. Its Fermi energy in eV (rounded off to one decimal place) is _____

(

J.s, mass of electron

kg, charge of electron =

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For a two-dimensional hexagonal lattice with lattice constant

, the atomic density is

Your answerChoose one option.

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Consider a crystal that has a basis of one atom. Its primitive vectors are

, where

are the unit vectors in the

and

directions of the Cartesian coordinate system and

is a positive constant. Which one of the following is the correct option regarding the type of the Bravais lattice?

Your answerChoose one option.

It is BCC and the volume of the primitive cell is

It is FCC and the volume of the primitive cell is

It is BCC and the volume of the primitive cell is

It is FCC and the volume of the primitive cell is

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As per the Drude model of metals, the electrical resistance of a metallic wire of length

and cross-section area

(Consider

as the relaxation time,

as electron mass,

as carrier concentration and

as electron charge)

Your answerChoose one option.

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Consider one mole of a monovalent metal at absolute zero temperature, obeying the free electron model. Its Fermi energy is

. The energy corresponding to the filling of

electrons, where

is the Avogadro number, is

. The value of

Your answerChoose one option.

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A paramagnetic material containing paramagnetic ions with total angular momentum

is kept at absolute temperature

. The ratio of the magnetic field required for 80% of the ions to be in the lowest energy state to that required for having 60% of the ions to be in the lowest energy state at the same temperature is

Your answerChoose one option.

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Powder X-ray diffraction pattern of a cubic solid with lattice constant

has the (111) diffraction peak at

. If the lattice expands such that the lattice constant becomes

, the angle (in degrees) corresponding to the (111) peak changes to

. The value of

(rounded off to one decimal place) is _____

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GATE PH Solid State Physics PYQs

How to practice Solid State Physics

Question 31

Question 32

Question 54

Question 63

Question 11

Question 12

Question 17

Question 22

Question 23

Question 33