GATE PH branch:ph PYQs & Answers — Page 9

Questions 81–90 of 650. Imported answers require independent review unless marked reviewed.

Topic practice 650 questionsPage 9 of 65

Which one of the following is correct for the phase velocity

and group velocity

? (

is the speed of light in vacuum)

Your answerChoose one option.

For matter waves in the relativistic case,

For electromagnetic waves in a medium,

represents the speed with which energy propagates

For electromagnetic waves in a medium, both

and

can be more than

For matter waves in free space,

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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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Which one of the following baryons has strangeness quantum number

Your answerChoose one option.

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A logic gate circuit is shown in the figure below. The correct combination for the input

for which the output

Your answerChoose one option.

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The nuclear energy levels of mirror nuclei are similar. Using this empirical fact alone, the nuclear force can be said to be independent of which one of the following properties of the nucleons?

Your answerChoose one option.

Mass

Spin

Charge

Parity

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Consider the function

of a complex variable

. The residues of the function at

and

, respectively, are

Your answerChoose one option.

and

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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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Which of the following option(s) is/are correct for the ground state of a hydrogen atom?

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

Linear Stark effect is zero

It has definite parity

Spin-orbit coupling is zero

Hyperfine splitting is zero

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Which of the following option(s) is/are correct for photons?

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

Its rest mass is zero, but its energy is non-zero

It carries non-zero linear momentum

It carries zero spin angular momentum

It has two linearly independent states of polarization

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GATE PH branch:ph PYQs

Question 16

Question 17

Question 18

Question 19

Question 20

Question 21

Question 22

Question 23

Question 24

Question 25