MCQs of Dual Nature of Radiation and Matter

Dual Nature of Radiation and Matter MCQs

MCQs of Dual Nature of Radiation and Matter

Showing 121 to 130 out of 186 Questions

121.

Ultraviolet radiation of 6.2 eV falls on an Aluminium surface, whose work function is 4.2 eV. This kinetic energy in joule of the fastest electron emitted is approximately _____ .

(a)	3.2×10^-21
(b)	3.2×10^-14
(c)	3.2×10^-17
(d)	3.2×10^-19

122.

X-rays are used to irradiate sodium and copper surface in two separate experiments and stopping potential is determined. This stopping potential is _____ .

(a)	equal in both cases
(b)	greater for sodium
(c)	greater for copper
(d)	infinite in both cases

123.

The threshold wavelength of sodium metal is 6800 Å The work function is _____ (hc= 1240 eV)

(a)	1.82 eV
(b)	3.64 eV
(c)	0.91 eV
(d)	2.73 eV

124.

In photoelectric emission, the velocity of electron ejected from near surface is _____ .

(a)	larger than the ones coming from interior of metal
(b)	less than those coming from interior of metal
(c)	same as those from interior of metal
(d)	None of these

125.

Which of the following is correct?

(a)	The current in photocell increases with applied voltage.
(b)	The photo current is proportional to the applied voltage.
(c)	The stopping potential increases with the intensity of the incident light.
(d)	The photo current increases with the intensity of the incident light.

126.

The threshold wavelength of the photo electric effect is

λ_{0}

. The energy of the electron ejected from the surface of silver by an incident light of wavelength

(λ > λ_{0})

will be _____ .

(a)	$h c (λ > λ_{0})$
(b)	$\frac{h c}{λ - λ_{0}}$
(c)	$\frac{h}{c} (\frac{1}{λ} - \frac{1}{λ_{0}})$
(d)	$h c (\frac{λ - λ_{0}}{λ λ_{0}})$

127.

A particle of mass 5 kg at rest decays into two particles of masses 2 kg and 3 kg having non-zero velocities. The ratio of de Broglie wavelengths of the particle is _____ .

(a)	$\frac{3}{2}$
(b)	$\frac{2}{3}$
(c)	$\frac{1}{3}$
(d)	None of these

128.

An electron and photon have same wavelength. If E is the energy of photon and p is momentum of electron, then the magnitude of

\frac{E}{p}

in SI unit is ______ .

(a)	$3.33 \times 10^{- 9}$
(b)	$3.0 \times 10^{8}$
(c)	$1.1 \times 10^{- 19}$
(d)	$9 \times 10^{16}$

129.

A particle with rest mass

m_{0}

is moving with speed of light c. The Broglie wavelength associated with it will be _____ .

(a)	$\infty$
(b)	zero
(c)	$\frac{m_{0} c}{h}$
(d)	$\frac{h}{m_{0} c}$

130.

An electron and proton are moving with the same speed. Mass of proton = 1836 times mass of electron. The ratio of their de Broglie wavelength will be _____ .

(a)	1
(b)	1836
(c)	$\frac{1}{1836}$
(d)	918

Showing 121 to 130 out of 186 Questions