Questions 251–260 of 380. Imported answers require independent review unless marked reviewed.

Topic practice 380 questionsPage 26 of 38

Question 32

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Which one of the following matrices does NOT represent a proper rotation in a plane?
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Question 33

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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
Diagram for Physics question 33

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Question 34

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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?
Diagram for Physics question 34

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Question 35

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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,
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Question 36

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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 to
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Question 37

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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 are
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Question 38

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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?
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Question 39

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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

is
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Question 1

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The fishermen, ______ the flood victims owed their lives, were rewarded by the government.
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Question 2

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Some students were not involved in the strike.
If the above statement is true, which of the following conclusions is/are logically necessary?
Some who were involved in the strike were students.
No student was involved in the strike.
At least one student was involved in the strike.
Some who were not involved in the strike were students.
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