NCERT Solutions for Class 12 Physics Chapter 12

NCERT Solutions for Class 12 Physics Chapter 12 Atom Exercises Solutions and Additional Exercises Solutions in PDF form as well as option for study online without downloading. Downloads of NCERT Sols of other subjects are also available to download.



NCERT Solutions for Class 12 Physics Chapter 12

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12 Physics Chapter 12 Exercises

NCERT Solutions for Class 12 Physics Chapter 12 Atom exercises are given below to use it online. Click here to see the Additional Exercises questions of this chapter or go to 12 Physics main page.
NCERT Solutions for Class 12 Physics Chapter 12 Atom




NCERT Solutions for Class 12 Physics Chapter 12 Atom in pdf form
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NCERT Solutions for Class 12 Physics Chapter 12 Atom all numerical problems
NCERT Solutions for Class 12 Physics Chapter 12 Atom all question answers



NCERT Solutions for Class 12 Physics Chapter 12 Atom free pdf download

12 Physics Chapter 12 Additional Exercises

NCERT Solutions for Class 12 Physics Chapter 12 Atom additional exercises are given below to use it online. Click here to see Exercises Questions or move to Top of the page or go to 12 Physics main page.
12 Physics Chapter 12 Atom additional exercises solutions




12 Physics Chapter 12 Atom additional exercises sols in pdf form
12 Physics Chapter 12 Atom additional exercises answers in free pdf




12 Physics Chapter 12 Atom additional exercises all question answers
12 Physics Chapter 12 Atom solutions

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Previous Chapter: Dual Nature of Radiation and Matter
Next Chapter: Nuclei

Practice Questions



  1. A 12.5 MeV alpha – particle approaching a gold nucleus is deflected by 180°. What is the closest distance to which it approaches the nucleus?
  2. Calculate the radius of the third Bohr orbit of hydrogen atom and energy of electron in that orbit.
  3. An electron and a proton are possessing same amount of K.E., which of the two have greater de-Broglie, wavelength? Justify your answer.
  4. For what Kinetic energy of a neutron will the associated de Broglie wavelength be 5.6 × 10^-10m?
  5. If the frequency of incident light in photoelectric experiment is doubled then does the stopping potential become double or more than double, justify?
  6. What will be the distance of closest approach of a 5 MeV proton as it approaches a gold nucleus?
  7. The radius of inner most orbit of Hydrogen atom is 5.3 × 10–1m. What are the radii of n = 2 and n = 8 orbits.
Try These
  • A metal surface illuminated by 8.5 × 1014 Hz light emits electrons whose maximum energy is 0.52 eV the same surface is illuminated by 12.0 × 1014 Hz light emits elections whose maximum energy is 1.97eV. From these data find work function of the surface and value of Planck’s constant. [Work Function = 3ev]
  • State the law of radioactive disintegration. Hence define disintegration constant and half life period. Establish relation between them.
  • State Bohr’s postulates. Using these postulates, drive an expression for total energy of an electron in the nth orbit of an atom. What does negative of this energy signify?
  • The total energy of an electron in the first excited state of the hydrogen atom is about –3.4 eV. What is
    (a) the kinetic energy, (b) the potential energy of the electron? (c) Which of the answers above would change if the choice of the zero of potential energy in changed to (i) + 0.5 eV (ii) –0.5 eV.