COMEDK 2025 Afternoon Shift | Ray Optics Question 7 | Physics

A ray of light is travelling from glass of refractive index $\frac{3}{2}$ to water of refractive Index $\frac{4}{3}$. What is the minimum angle of incidence for which no light enters in to the water?

$i_c=\sin ^{-1}\left(\frac{9}{8}\right)$

$i_c=\sin ^{-1}\left(\frac{8}{9}\right)$

$i_c=\sin ^{-1}\left(\frac{2}{3}\right)$

$i_c=\sin ^{-1}\left(\frac{1}{2}\right)$

COMEDK 2025 Afternoon Shift

MCQ (Single Correct Answer)

-0

The focal lengths of the objective and eyepiece of a compound microscope are 1 cm and 10 cm respectively. Length of the tube is 25 cm . If the final image is formed at infinity , the magnifying power of the microscope is :

7.0

3.5

COMEDK 2025 Afternoon Shift

MCQ (Single Correct Answer)

-0

What is the velocity of light in vacuum if the velocity of light in a medium of refractive index 1.2 is ' v ' $\mathrm{ms}^{-1}$ ?

$\left(\frac{v}{1.2}\right) m s^{-1}$

$(2.4 v) \mathrm{ms}^{-1}$

$(1.2 v) \mathrm{ms}^{-1}$

$3 \times 10^8 \mathrm{~ms}^{-1}$

COMEDK 2025 Morning Shift

MCQ (Single Correct Answer)

-0

One surface of a lens is convex and the other is concave. If the radii of curvatures are $R$ and $r$ respectively, the lens will be convex if

$R >r$

$R< r$

$R=\frac{1}{r}$

$R=r$

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