MCQs of Dual Nature of Radiation and Matter

Dual Nature of Radiation and Matter MCQs

MCQs of Dual Nature of Radiation and Matter

Showing 171 to 180 out of 186 Questions

171.

Radius of a nucleus is 2×10^-15 m. If we imagine electron inside the nucleus, then energy of electron will be _____ MeV. h=6.6×10^-24 J.sec , m_c=9.1×10^-31 kg

(a)	6.38×10³
(b)	8.94×10³
(c)	4.98×10³
(d)	2.37×10³

172.

Compare energy of a photon of X-rays having 1Å , wavelength with the energy of an electron having same de Broglie wavelength. (h=6.6×10^-24 J.sec , c=3×10⁸ ms^-1 , M_e=9.1×10^-31 kg )

(a)	8.24
(b)	2.48
(c)	82.4
(d)	24.8

173.

Wavelength of an electron having energy E is

λ_{0} = \frac{h}{\sqrt{2 mE}}

, where m is the mass of an electron. Find the wavelength of the electron when it enter in X-direction in the region having potential V(x). If we imagine that due to the potential, electron enters from one medium to another, what is the refractive index of the medium ?

(a)	$λ = \frac{2 mE}{{eVx}^{\frac{1}{2}}}, μ = {[\frac{eVx}{E}]}^{\frac{1}{2}}$
(b)	$λ = \frac{h}{2 m {[E + eV (x)]}^{\frac{1}{2}}}, μ = {[\frac{E + eV (x)}{E}]}^{\frac{1}{2}}$
(c)	$λ = \frac{h {[E + eV (x)]}^{\frac{1}{2}}}{2 m}, μ = {[\frac{E}{E + eV (x)}]}^{\frac{1}{2}}$
(d)	$λ = \frac{Eh}{2 m {[E + eV (x)]}^{\frac{1}{2}}}, μ = \frac{{(eV (x))}^{\frac{1}{2}}}{E}$

174.

Consider the radius of a nucleus to be 10^-15 m . If an electron is assumed to be in such nucleus, what will be its energy ? ( Mass of electron M_e=9.1×10^-31 kg , h=6.6×10^-24 J.sec )

(a)	5.59×10³
(b)	9.55×10³
(c)	5.95×10³
(d)	7.45×10³

175.

Find the wave packet formed due to the superposition of two harmonic waves represented by

y_{1} = A \sin (ωt - kx) and y_{2} = A \sin [(ω + dω) t - (k + dk) x]

(a)	$2 Acos (\frac{xdk - tdω}{2})$
(b)	$2 Asin (\frac{xdk - tdω}{2})$
(c)	$2 Acos (\frac{tdω - xdk}{2})$
(d)	$2 Asin (\frac{tdω - xdk}{2})$

176.

A small piece of Cs (work function = 1.9 eV) is placed 22 cm away from a large metal plate. The surface charge density on the metal plate is 1.21×10^-9 Cm^-2 . Now, light of 460 nm wavelength is incident on the piece of Cs. Find he maximum and minimum energies of photo electrons on reaching the plate. Assume that no charge occur in electric filed produced by the plate due to the piece of Cs.

(a)	E_min=29.83 eV, E_max= 30.63 eV
(b)	E_min=0 eV, E_max= 29.83 eV
(c)	E_min=0 eV, E_max= 30.63 eV
(d)	E_min=0 eV, E_max= 0 eV

177.

Wavelength of light incident on a photo-sensitive surface is reduced from 3500 Å to 290 nm. The change in stopping potential is _____ . (h=6.625×10^-34 J.sec )

(a)	42.73×10^-2 V
(b)	27.34×10^-2 V
(c)	73.42×10^-2 V
(d)	43.27×10^-2 V

178.

An electric bulb of 100 W converts 3 % of electrical energy into light energy. If the wavelength of light emitted is 6625 Å , the number of photons emitted in 1 s is _____ . (h=6.625×10^-34 J.sec )

(a)	10¹⁷
(b)	10¹⁹
(c)	10²¹
(d)	10¹⁵

179.

Work function of Zn is 3.74 ev. If the sphere of Zn is illuminated by the X-rays of wavelength 12 Å , the maximum potential produced on the sphere is _____ .(h=6.625×10^-34 J.sec)

(a)	10.314 V
(b)	103.14 V
(c)	1031.4 V
(d)	10314 V

180.

Human eye can experience minimum 19 photons per second. Light of 560 nm wavelength is required for it. What is the minimum power necessary to excite optic nerves?

(a)	6.74×10^-19 W
(b)	67.44×10^-19 W
(c)	0.674×10^-19 W
(d)	674×10^-19 W

Showing 171 to 180 out of 186 Questions