Download App

Geometrical Optics — Physics STD 12 Science — Question

Rajasthan BoardEnglish MediumSTD 12 SciencePhysicsGeometrical Optics1 Mark
Question
Total internal reflection can take place only if:
  1. Light goes from optically rarer medium $($smaller refractive index$)$ to optically denser medium.
  2. Light goes from optically denser medium to rarer medium.
  3. The refractive indices of the two media are close to each other.
  4. The refractive indices of the two media are widely different.
✓

Answer

$\text{T.I.R}. ($Total Internal reflection$)i < C ($condition for $\text{T.I.R})$
By Snell's Law
$\text{n}_1\sin\text{i}=\text{n}_2\sin90^{\circ}$
$\sin\text{i}=\frac{\text{n}_2}{\text{n}_1}=\sin\text{C}$
$\text{þ} \ \text{C}=\sin^{-1}$
$\because \ -1\leq\sin\text{i}\leq1$
$n_1 > n_2 ($so we can conclude that light goes from optically denser medium to rarer medium incident angle is greater than the critical angle.$)$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from Geometrical Optics→Geometrical Optics — all question types→Physics STD 12 Science question papers→Rajasthan Board STD 12 Science question papers→Rajasthan Board question paper generator→

Similar questions

The number of revolutions per second made by an electron in the first Bohr orbit of hydrogen atom is of the order of $3$
→
A piece of charcoal and a piece of shining steel of the same surface area are kept for a long time in an open lawn in bright sun:
  1. The steel will absorb more heat than the charcoal.
  2. The temperature of the steel will be higher than that of the charcoal.
  3. If both are picked up by bare hands, the steel will be felt hotter than the charcoal.
  4. If the two are picked up from the lawn and kept in a cold chamber, the charcoal will lose heat at a faster rate than the steel.
→
99% of a radioactive element will decay between(a) 6 and 7 half lives(b) 7 and 8 half lives(c) 8 and 9 half lives(d) 9 half lives
   
   
→
The energy required to charge a capacitor of 5μF  by connecting a d.c. source of 20 kV is(a) 10 kJ  (b) 5 kJ(c) 2 kJ    (d) 1 kJ
       
→
Samples of two radioactive nuclides $A$ and $B$ are taken. $\lambda A$ and $\lambda B$ are the disintegration constants of $A$ and $B$ respectively. In which of the following cases, the two samples can simultaneously have the same decay rate at any time?
→
Gold-leaf electroscope can be used _______?
→
A point object O is placed on the principal axis of a convex lens of focal length 20 cm at a distance of 40 cm to the left of it. The diameter of the lens is 10 cm. If the eye is placed 60 cm to the right of the lens at a distance h below the principal axis, then the maximum value of h to see the image will be(a) 0 (b) 5 cm(c) 2.5 cm(d) 10 cm
       
→
A conducting rod of length L is falling with velocity v perpendicular to a uniform horizontal magnetic field B. The potential difference between its two ends will be.
→
Among which of the following the magnetic susceptibility does not depend on the temperature?
→
The minimum number of condensers each of capacitance of $2μ\text{F},$ in order to obtain resultant capacitance of $5μ\text{F},$ will be:
→