Physics Scoring Tips – Units 6, 7, 8

CBSE has given maximum weightage to the unit Optics with one long answer and some very short and short type answers. Units such as Dual Nature of Radiation and Matter,  Atoms and Nuclei are given low weightage but they are highly scoring if one remembers the formulae, definitions and graphs.

Unit 6: OPTICS (14 marks)

Want to secure a full-five marks score in optics?
A smart way of doing this is practising previous years’ questions and getting common questions. Here is a quick analysis of topics on which questions were asked repeatedly by CBSE in the five marks question pattern.

(You may go through the detailed solution of the board papers by clicking on the hyperlinks)

This analysis gives a clear idea of repetition of questions in board papers. Few topics which are very much essential for further study in physics will always be tested in the board exams.

More the number of previous papers solved, higher the chance of getting COMMON QUESTIONS. Click here for previous years’ board papers.

Unit 7: Dual Nature of Radiation and Matter (4 marks)

Q: An electron is accelerated through a potential difference of 64 volts. What is the de-Broglie wavelength associated with it? To which part of the electromagnetic spectrum does this value of wavelength correspond?   (CBSE 2010, 2 marks)

This question can be easily solved if you know the application of the formula:

Unit 8: Atoms and Nuclei (6 marks)

For mastering this unit you need to master the formulae. Make a list of all the important formulae in this unit with at least one application in numerical solving. Questions from this units are basically definitions, graphs and formula based numericals.

Q: The energy levels of an atom are as shown below. Which of them will result in the transition of a photon of wavelength 275 nm?Which transition corresponds to emission of radiation of maximum wavelength?     (CBSE 2009, 3 marks)

The formula E = hc/λ is sufficient to give you three marks in this question.

So, for this unit make sure you go through Rutherford’s model, Bohr’s model, Hydrogen spectra, Radioactive decays, Nuclear reactions (fission and fusion).

Follow these simple things and we are sure that you’ll manage to add the entire 24 marks from these units into your account.

To revise the formulae based on these units, click on the link: Formula Sheet ( Unit  6, 7, 8 )

Good Luck!
Team Meritnation