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50% of X-rays obtained from a Coolidge tube pass through 0.3 mm. thick aluminium foil. If the potential difference between the target and the cathode is increased, then the fraction of X-rays passing through the same foil will be :-

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Important Questions on Atomic Physics

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Physics>Modern Physics>Atomic Physics>X - Rays

The frequency of

K_{a}

line of a source of atomic number

z

is proportional to

HARD

Physics>Modern Physics>Atomic Physics>X - Rays

A student is jogging on a straight path with the speed $5.4 km$ per hour. Perpendicular to the path is kept a pipe with its opening $8 m$ from the road (see figure). Diameter of the pipe is $0.45 m$ At the other end of the pipe is a speaker emitting sound of $1280 Hz$ towards the opening of the pipes. As the student passes in front of the pipe, she hears the speaker sound for $T$ seconds. $T$ is in the range (take speed of sound, $320 {ms}^{- 1}$ ):

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Physics>Modern Physics>Atomic Physics>X - Rays

Wavelength of characteristic X-ray depends on which property of target?

(where, A = Mass number, Z = Atomic number)

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Physics>Modern Physics>Atomic Physics>X - Rays

The waves emitted when a metal target is bombarded with high energy electrons are

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Physics>Modern Physics>Atomic Physics>X - Rays

Electrons of mass,

m

with de-Broglie wavelength,

λ

fall on the target in an X-ray tube. The cutoff wavelength,

(λ_{0})

of the emitted X-ray is

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Physics>Modern Physics>Atomic Physics>X - Rays

The

K_{α}

X-ray of molybdenum has wavelength

0.071 nm

. If the energy of a molybdenum atom with a

K

electron knocked out is

27.5 keV

, the energy of this atom when an

L

electron is knocked out will be

keV

. (Round off to the nearest integer )

[h = 4.14 \times 10^{- 15} eV s, c = 3 \times 10^{8} {m s}^{- 1}]

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Physics>Modern Physics>Atomic Physics>X - Rays

An X-ray tube is operated at

1.24

million volt. The shortest wavelength of the produced photon will be:

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Physics>Modern Physics>Atomic Physics>X - Rays

K_{α}

radiation of

M o (Z = 42)

has a wavelength

0.71 \overset{o}{A}

, then the wavelength of the corresponding radiation of

C u (Z = 29)

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Physics>Modern Physics>Atomic Physics>X - Rays

An electron beam is accelerated by a potential difference

V

to hit a metallic target to produce

X -

rays. It produces continuous as well as characteristic

X -

rays. If

λ_{m i n}

is the smallest possible wavelength of

X -

ray in the spectrum, the variation of

\log (λ_{m i n})

with

\log (V)

is correctly represented in :

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Physics>Modern Physics>Atomic Physics>X - Rays

λ_{Cu}

is the wavelength of

K_{α}

X -

ray line of copper (atomic number

29

) and

λ_{M o}

is the wavelength of the

K_{α}

X -

ray line of molybdenum (atomic number

42

), then the ratio

\frac{λ_{Cu}}{λ_{M o}}

is close to

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Physics>Modern Physics>Atomic Physics>X - Rays

What are cathode rays?

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Physics>Modern Physics>Atomic Physics>X - Rays

The shortest wavelength of

X

-rays emitted from an

X

-ray tube depends upon

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Physics>Modern Physics>Atomic Physics>X - Rays

W. K. Roentgen discovered

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Physics>Modern Physics>Atomic Physics>X - Rays

X-rays consists of

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Physics>Modern Physics>Atomic Physics>X - Rays

Which wave or ray is produced due to decelerating or accelerating charged particles?

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Physics>Modern Physics>Atomic Physics>X - Rays

The wavelengths of

K_{a}

x

-rays of two metals

‘ A ’

and

‘ B ’

are

\frac{4}{1875 R}

and

\frac{1}{675 R}

respectively, where

‘ R ’

is rydberg constant. The number of elements lying between

‘ A ’

and

‘ B ’

according to their atomic numbers is________

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Physics>Modern Physics>Atomic Physics>X - Rays

The

k

-line of singly ionized calcium has a wavelength of

393.3 nm

as measured on earth. In the spectrum of one of the observed galaxies, this spectral line is located at

401.8 nm

. The speed with which the galaxy is moving away from us, will be

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Physics>Modern Physics>Atomic Physics>X - Rays

For the structural analysis of crystals,

X -

rays are used because:

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Physics>Modern Physics>Atomic Physics>X - Rays

In a discharge tube when

200 volt

potential difference is applied

6.25 \times 10^{18}

electrons move from cathode to anode and

3.125 \times 10^{18}

singly charged positive ions move from anode to cathode in one second. Then the power of tube is:

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Physics>Modern Physics>Atomic Physics>X - Rays

The energy of a photon of a characteristic X-ray from a Coolidge tube comes from

50% of X-rays obtained from a Coolidge tube pass through 0.3 mm. thick aluminium foil. If the potential difference between the target and the cathode is increased, then the fraction of X-rays passing through the same foil will be :-

Important Questions on Atomic Physics

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