MCQ
Light wave enters from medium $1$ to medium $2.$ Its velocity in $2^{nd}$ medium is double from $1^{st}$. For total internal reflection the angle of incidence must be greater than.......$^o$
- ✓$30$
- B$60 $
- C$45 $
- D$90$
✓
Answer
Correct option: A.
$30$
a
(a) $\frac{{{\mu _2}}}{{{\mu _1}}} = \frac{{{v_1}}}{{{v_2}}} = \frac{1}{2} \Rightarrow \frac{{{\mu _1}}}{{{\mu _2}}} = 2({\mu _1} > {\mu _2})$
For total internal reflection $_2{\mu _1} = \frac{1}{{\sin C}} \Rightarrow \frac{{{\mu _1}}}{{{\mu _2}}}$
$ = \frac{1}{{\sin C}} \Rightarrow 2 = \frac{1}{{\sin C}} \Rightarrow C = {30^o}$
So, for total (Internal reflection angle of incidence must be greater than $30°.$
(a) $\frac{{{\mu _2}}}{{{\mu _1}}} = \frac{{{v_1}}}{{{v_2}}} = \frac{1}{2} \Rightarrow \frac{{{\mu _1}}}{{{\mu _2}}} = 2({\mu _1} > {\mu _2})$
For total internal reflection $_2{\mu _1} = \frac{1}{{\sin C}} \Rightarrow \frac{{{\mu _1}}}{{{\mu _2}}}$
$ = \frac{1}{{\sin C}} \Rightarrow 2 = \frac{1}{{\sin C}} \Rightarrow C = {30^o}$
So, for total (Internal reflection angle of incidence must be greater than $30°.$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
A moving coil galvanometer allows a full scale current of $10^{-4}\, A$. A series resistance of $2\, M\,\Omega $ is required to convert the above galvanometer into a voltmeter of range $0 -5\, V$. Therefore the value of shunt resistance required to convert the above galvanometer into a ammeter of range $0-10\, mA$ is....$\Omega $
→In the circuit shown in figure the maximum output voltage $V_0$ is....$ V$
→Given below are two statements :
→Statement $I$ : When the white light passed through a prism, the red light bends lesser than yellow and violet.
Statement $II$ : The refractive indices are different for different wavelengths in dispersive medium. In the light of the above statements, choose the correct answer from the options given below :
A thin insulator rod is placed between two unlike point charges $+q_1$ and $q_2$. For this situation tick the correct alternative (s):
→What is the potential difference between $A$ and $B$ in the circuit shown.......$V$
→Hydrogen atom excites energy level from fundamental state to $n = 3.$ Number of spectrum lines according to Bohr, is
→In the middle of the depletion layer of a reverse-biased $PN$ junction, the
→Which one is in forward bias
The critical angle for a medium is ${60^o}$. The refractive index of the medium is
→The equivalent resistance of the circuit shown in the figure is
