NCERT MCQ CLASS-12 CHAPTER-12 | PHYSICS NCERT MCQ | ATOMS | EDUGROWN

In This Post we are  providing Chapter-12 Atom NCERT MCQ for Class 12 Physics which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ATOMS

Question 1.
De-Broglie equation states the:
(a) dual nature
(b) particle nature
(c) wave nature
(d) none of these

Answer: (a) dual nature

Question 2.
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: (d) Momentum

Question 3.
Kinetic energy of emitted electrons depends upon :
(a) frequency
(b) intensity
(c) nature of atmosphere surrounding the electrons
(d) none of these

Answer: (a) frequency

Question 4.
De-Broglie wavelength of a body of mass m and kinetic energy E is given by (symbols have their usual meanings):
(a) h/2m√E
(b) h/2mE
(c) 2mE/√h
(d) h/mE

Answer: (a) h/2m√E

Question 5.
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: (a) 1 : 2

Question 6.
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: (d) the no. of isotopes of the element present

Question 7.
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: (a) 8 × 10¹⁴ Hz

Question 8.
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: (b) frequency of incident radiation

Question 9.
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: (b) 3.3 × 10^-24 kgms^-1

Question 10.
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: (c) Faraday

Question 11.
Millikan’s oil drop experiment makes use of:
(a) Stokes’ law
(b) Boyle’s law
(c) Gas equation
(d) Bernoulli’s theorem

Answer: (a) Stokes’ law

Question 12.
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: (d) not deflected by electric and magnetic fields

Question 13.
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: (a) visible region

Question 14.
Which of the following radiations cannot eject photo electrons?
(a) ultraviolet
(b) infrared
(c) visible
(d) X-rays

Answer: (b) infrared

Question 15.
What is the de-Broglie wavelength of an electron accelerated from rest through a potential difference of V volts?
(a) 12.3V2 Å
(b) 12.3V Å
(c) 12.2V2 Å
(d) None of these

Answer: (a) 12.3V2 Å

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