1
JEE Main 2019 (Online) 12th April Evening Slot
+4
-1
A transparent cube of side, made of a material of refractive index $$\mu$$2, is immersed in a liquid of refractive index $$\mu$$1($$\mu$$1 < $$\mu$$2). A ray is incident on the face AB at an angle $$\theta$$(shown in the figure). Total internal reflection takes place at point E on the face BC.
Then $$\theta$$ must satisfy :
A
$$\theta > {\sin ^{ - 1}}\sqrt {{{\mu _2^2} \over {\mu _1^2}} - 1}$$
B
$$\theta < {\sin ^{ - 1}}\sqrt {{{\mu _2^2} \over {\mu _1^2}} - 1}$$
C
$$\theta < {\sin ^{ - 1}}{{{\mu _1}} \over {{\mu _2}}}$$
D
$$\theta > {\sin ^{ - 1}}{{{\mu _1}} \over {{\mu _2}}}$$
2
JEE Main 2019 (Online) 12th April Evening Slot
+4
-1
A system of three polarizers P1, P2, P3 is set up such that the pass axis of P3 is crossed with respect to that of P1. The pass axis of P2 is inclined at 60o to the pass axis of P3. When a beam of unpolarized light of intensity I0 is incident on P1, the intensity of light transmitted by the three polarizers is I. The ratio ($${{{I_0}} \over I}$$) equals (nearly) :
A
10.67
B
5.33
C
16.00
D
1.80
3
JEE Main 2019 (Online) 12th April Morning Slot
+4
-1
The value of numerical aperature of the objective lens of a microscope is 1.25. If light of wavelength 5000 $$\mathop A\limits^o$$ is used, the minimum separation between two points, to be seen as distinct, will be :
A
0.12 $$\mu$$m
B
0.38 $$\mu$$m
C
0.24 $$\mu$$m
D
0.48 $$\mu$$m
4
JEE Main 2019 (Online) 12th April Morning Slot
+4
-1
In a double slit experiment, when a thin film of thickness t having refractive index $$\mu$$. is introduced in front of one of the slits, the maximum at the centre of the fringe pattern shifts by one fringe width. The value of t is ($$\lambda$$ is the wavelength of the light used) :
A
$${\lambda \over {2\left( {\mu - 1} \right)}}$$
B
$${\lambda \over {\left( {2\mu - 1} \right)}}$$
C
$${{2\lambda } \over {\left( {\mu - 1} \right)}}$$
D
$${\lambda \over {\left( {\mu - 1} \right)}}$$
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