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Rajasthan Board Class 12 (RBSE) Waves & Oscillations — practice questions

Explore 25 free Waves & Oscillations questions in Rajasthan Board Class 12 (RBSE) Physics. Open each question or exercise to read its content, reference answers and available explanation.

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Waves & Oscillations questions and exercises with answers

Showing questions 1–25 of 25.

Unpolarised light of intensity $I_0$ is passed through a single ideal polariser. The intensity of the transmitted light is:Read the answer and worked solution →Brewster's angle for a glass of refractive index $\sqrt{3}$ (relative to air) is:Read the answer and worked solution →Order the atomic models in this chapterRead the answer and worked solution →True or false: Rutherford's two difficultiesRead the answer and worked solution →Which model does this belong to?Read the answer and worked solution →Complete Bohr's first postulateRead the answer and worked solution →True or false: line spectraRead the answer and worked solution →Charge and neutralityRead the answer and worked solution →Assertion and reasonRead the answer and worked solution →Two are true, one is notRead the answer and worked solution →Three of these are wrong. Find the one that holds.Read the answer and worked solution →Tap every problem Bohr's model was built to solveRead the answer and worked solution →Flip and pair: model with its pictureRead the answer and worked solution →Spot the one that does not belongRead the answer and worked solution →Strength or weakness?Read the answer and worked solution →Complete the size of the nucleusRead the answer and worked solution →Reading the models backRead the answer and worked solution →Bohr's postulatesRead the answer and worked solution →Explained, or left unexplained?Read the answer and worked solution →True or false: the nucleusRead the answer and worked solution →Order the argument: why Rutherford's atom should collapseRead the answer and worked solution →Two are true, one is notRead the answer and worked solution →Assertion and reason: modelsRead the answer and worked solution →Spot the one that does not belongRead the answer and worked solution →Flip and pair: problem with the model that solved itRead the answer and worked solution →

Worked practice questions

Unpolarised light of intensity $I_0$ is passed through a single ideal polariser. The intensity of the transmitted light is:

  1. $I_0$
  2. $I_0/2$
  3. $I_0\cos^2\theta$
  4. $I_0/4$
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Correct answer: B. $I_0/2$

Unpolarised light contains all polarisation directions with equal probability. Averaging Malus's law over all input angles gives $\langle I \rangle = I_0 \langle\cos^2\theta\rangle = I_0/2$. Once polarised, a second polariser would then attenuate further by $\cos^2\theta$ relative to its axis.

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Brewster's angle for a glass of refractive index $\sqrt{3}$ (relative to air) is:

  1. $30^\circ$
  2. $45^\circ$
  3. $60^\circ$
  4. $90^\circ$
Show answer and solution

Correct answer: C. $60^\circ$

**Brewster's law:** $\tan i_B = \mu$. With $\mu = \sqrt{3}$, $\tan i_B = \sqrt{3} \Rightarrow i_B = 60^\circ$. At this angle the reflected light is completely plane-polarised, with the electric field perpendicular to the plane of incidence.

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Order the atomic models in this chapter

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Steps
  1. Thomson: a sphere of positive charge with electrons embedded in it
  2. Rutherford: mass and positive charge concentrated in a tiny nucleus
  3. Bohr: electrons in stable stationary orbits, from three postulates
Thomson, then Rutherford, then Bohr, each answering the last one's failure. Source: syllabus Physics, Ch 12 Atoms.

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More Physics topics

Moving Charges and MagnetismMagnetismRay OpticsRay Optics and Optical InstrumentsElectromagnetismAtomsOpticsRay and Wave Optics