Thursday, 28 January 2021

CBSE Class 12 Physics - MCQ and Online Tests - Unit 11 - Dual Nature of Radiation and Matter

CBSE Class 12 Physics – MCQ and Online Tests – Unit 11 – Dual Nature of Radiation and Matter

Every year CBSE conducts board exams for 12th standard. These exams are very competitive to all the students. So our website provides online tests for all the 12th subjects. These tests are also very effective and useful for those who preparing for competitive exams like NEET, JEE, CA etc. It can boost their preparation level and confidence level by attempting these chapter wise online tests.

These online tests are based on latest CBSE Class 12 syllabus. While attempting these our students can identify the weak lessons and continuously practice those lessons for attaining high marks. It also helps to revise the NCERT textbooks thoroughly.


 

CBSE Class 12 Physics – MCQ and Online Tests – Unit 11 – Dual Nature of Radiation and Matter

Question 1.
The momentum of an electron that emits a wavelength of 2 Å. will be:
(a) 6.4 × 10-36 kgms-1
(b) 3.3 × 10-24 kgms-1
(c) 3.3 × 10-34 kgms-1
(d) none of these

Answer

Answer: (b) 3.3 × 10-24 kgms-1


Question 2.
Name the scientists who first studied the passage of electricity through fluids to establish the electrical nature of matter:
(a)Millikan
(b) Planck
(c) Faraday
(d) Boyle

Answer

Answer: (c) Faraday


Question 3.
The different stages of discharge in a discharge tube can be explained on the basis of:
(a) the wave nature of light
(b) the dual nature of light
(c) wave nature of electrons
(d) the collision between the charged particles emitted from the cathode the atoms of the gas in the tube

Answer

Answer: (d) the collision between the charged particles emitted from the cathode the atoms of the gas in the tube


Question 4.
Protons and alpha particles have the same de-Broglie wavelength. What is same for both of them ?
(a) Energy
(b) Time period
(c) Frequency
(d) Momentum

Answer

Answer: (d) Momentum


Question 5.
Millikan’s oil drop experiment makes use of:
(a) Stokes’ law
(b) Boyle’s law
(c) Gas equation
(d) Bernoulli’s theorem

Answer

Answer: (a) Stokes’ law


Question 6.
Kinetic energy of emitted electrons depends upon :
(a) frequency
(b) intensity
(c) nature of atmosphere surrounding the electrons
(d) none of these

Answer

Answer: (a) frequency


Question 7.
X-rays are:
(a) deflected by an electric field
(b) deflected by a magnetic field
(c) deflected by both electric and magnetic fields
(d) not deflected by electric and magnetic fields

Answer

Answer: (d) not deflected by electric and magnetic fields


Question 8.
De-Broglie wavelength of a body of mass m and kinetic energy E is given by (symbols have their usual meanings):
(a) \(\frac{h}{\sqrt{2mE}}\)
(b) \(\frac{h}{2mE}\)
(c) \(\frac{\sqrt{2mE}}{h}\)
(d) \(\frac{h}{mE}\)

Answer

Answer: (a) \(\frac{h}{\sqrt{2mE}}\)


Question 9.
In photo electric emission, for alkali metals the threshold frequency lies in the:
(a) visible region
(b) ultraviolet region
(c) infrared region
(d) far end of the infrared region

Answer

Answer: (a) visible region


Question 10.
The charge of a photo electron is :
(a) 9.1 × 10-31 C
(b) 9.1 × 10-27 C
(c) 9.1 × 10-24 C
(d) none of these

Answer

Answer: (d) none of these


Question 11.
The ratio of specific charge of an alpha particle to the proton is:
(a) 1 : 2
(b) 2 : 1
(c) 4 : 1
(d) 1 : 4

Answer

Answer: (a) 1 : 2


Question 12.
Which of the following radiations cannot eject photo electrons?
(a) ultraviolet
(b) infrared
(c) visible
(d) X-rays

Answer

Answer: (b) infrared


Question 13.
What is the de-Broglie wavelength of an electron accelerated from rest through a potential difference of V volts?
(a) \(\frac{12.3}{V^2}\) Å
(b) \(\frac{12.3}{V}\) Å
(c) \(\frac{12.2}{V^2}\) Å
(d) None of these

Answer

Answer: (a) \(\frac{12.3}{V^2}\) Å


Question 14.
What is the de-Broglie wavelength of an electron accelerated from rest through a potential difference of 100 volts?
(a) 12.3 Å
(b) 1.23 Å
(c) 0.123 Å
(d) None of these

Answer

Answer: (b) 1.23 Å


Question 15.
In Thomson’s experiment number of parabola gives :
(a) the no. of electrons present in element
(b) the no. of proton present in element
(c) the no. of neutrons present in element
(d) the no. of isotopes of the element present

Answer

Answer: (d) the no. of isotopes of the element present


Question 16.
What is the de-Broglie wavelength of a proton accelerated from rest through a potential difference of V volts?
(a) \(\frac{12.3}{√V}\) Å
(b) \(\frac{12.3}{V}\) Å
(c) \(\frac{12.2}{V^2}\) Å
(d) None of these

Answer

Answer: (d) None of these


Question 17.
which Characteristic of a target does the Mosley’s law relate the frequency of X-rays?
(a) density
(b) atomic number
(c) atomic weight
(d) interatomic space

Answer

Answer: (b) atomic number


Question 18.
When a yellow light is incident on a surface, no electrons are emitted while green light can emit electrons. If the red light is incident on the surface then:
(a) no electrons are emitted
(b) photons are emitted
(c) electrons of higher energy are emitted
(d) electrons of lower energy are emitted

Answer

Answer: (a) no electrons are emitted


Question 19.
De-Broglie equation states the:
(a) dual nature
(b) particle nature
(c) wave nature
(d) none of these

Answer

Answer: (a) dual nature


Question 20.
The de-Broglie wavelength of particle of mass 1 mg moving with a velocity of 1 ms-1, in terms of Planck’s constant h, is given by (in metre):
(a) 105 h
(b) 106 h
(c) 10-3 h
(d) 103 h

Answer

Answer: (b) 106 h


Question 21.
The work function of photoelectric material is 3.3 eV. The threshold frequency will be equal to:
(a) 8 × 1014 Hz
(b) 8 × 1010 Hz
(c) 5 × 1010 Hz
(d) 4 × 1014 Hz

Answer

Answer: (a) 8 × 1014 Hz


Question 22.
The strength of photoelectric current depends upon :
(a) angle of incident radiation
(b) frequency of incident radiation
(c) intensity of incident radiation
(d) distance between anode and cathode

Answer

Answer: (b) frequency of incident radiation


Question 23.
Evidence of the wave nature of light cannot be obtained from:
(a) diffraction
(b) interference
(c) doppler effect
(d) reflection

Answer

Answer: (d) reflection


Question 24.
The number of photons of frequency n present in energy E, in terms of Planck’s constant h:
(a) \(\frac{E}{nh}\)
(b) nhE
(c) \(\frac{nh}{E}\)
(d) \(\frac{nE}{h}\)

Answer

Answer: (a) \(\frac{E}{nh}\)


Question 25.
Compared to liquids and solids, gases are:
(a) good conductors of electricity
(b) best conductors of electricity
(c) very poor conductors of electricity
(d) good or bad conductors of electricity depending upon the nature of the gas

Answer

Answer: (c) very poor conductors of electricity


 

Share:

0 comments:

Post a Comment

In Article

Definition List

Unordered List

Support