Modern Physics Test

Result

Modern Physics Test - 3

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

The de-Broglie wavelength associated with a proton moving with a velocity, equal to 1/20 th of the velocity of light

A
2.834×10^-14 m

B
1.5×10^-7m

C
1.5×10⁷ m

D
2.634×10¹⁴ m

Solution
Question 2
1 / -0

An electron has been accelerated from rest through a potential difference of 100V, its de-Broglie wavelength is

A
225Å

B
1.225Å

C
225m

D
1.225cm

Solution
Question 3
1 / -0

The experiments of Frank and Hertz showed that

A
an atom has energy states having a continuous distribution

B
nothing can be send a bond energy states of atom

C
at atom has energy states, having discrete values

D
atom is an indivisible particle

Solution

The series of experiments by Frank and Hertz in 1914 produced direct evidence for energy levels in atoms. In studying the motion of electron through mercury vapour under the action of an electric field, they observed that the spectrum line at 254 nm was emitted by the vapour when the electrokinetic energy was greater than 4.9 eV. But there was no spectrum line when kinetic energy was found less than 4.9 eV.
Question 4
1 / -0

A photon and an electron have same energy, the ratio of their wavelengths is

A

B

C

D

Solution
Question 5
1 / -0

If the wavelength of incident light changes from 400nm to 300nm, the stopping potential for photoelectrons emitted from a surface becomes approximately

A
1.0V greater

B
1.0V smaller

C
0.5V greater

D
0.5V smaller

Solution
Question 6
1 / -0

The photosensitive surface is receiving light of wavelength 5000Å at the rate of 10^-8 Js^-1. The number of photons received per second, is

A
2.5 x 10¹⁰

B
2.5 x 10¹¹

C
2.5 x 10¹²

D
2.5 x 10⁹

Solution
Question 7
1 / -0

The wavelength of quantum of radiant energy emitted, if an electron transmitted into radiation and converted into one quantum, is

A
0.0242Å

B
2.42Å

C
532Å

D
0.532Å

Solution

when an energy of an electron is transmitted into radiation, we have
Question 8
1 / -0

The electric potential at the surface of an atomic nucleus (Z=50) of radius 9.0 x 10^-13 cm, is

A
9x 10⁵ V

B
8 x 10⁶ V

C
80V

D
9V

Solution

Electric potential at the surface of an atomic nucleus is
Question 9
1 / -0

Kα wavelength emitted by an atom of atomic number Z=11 is λ. Find the atomic number for an atom that emits Kα radiation with wavelength 4λ, is

A
Z=6

B
Z=4

C
Z=11

D
Z=44

Solution
Question 10
1 / -0

The ratio of minimum wavelengths of Lyman and Balmer series will be

A
1.25

B
0.25

C
5

D
10

Solution