Numerical aperture of an optical fiber is a measure of

light gathering power of the fiber

attenuation of light signals in the fiber

difference between the refractive indices of core and the cladding

A concave glass lens of refractive index 1 . 5 is immersed in carbon di-sulfide (refractive index = 1 . 6 ). Which of the following is true? [ Assume both surfaces of the lens have same radius of curvature = R ]

It will behave as convergent lens with focal length 8 R

It will behave as divergent lens with focal length 8 R

It will behave as convergent lens with focal length 7 . 5 R

It will behave as divergent lens with focal length 7 . 5 R

E M B I B E

Physics Crash Course NEET>Chapter 17 - Ray Optics>Level 2>Q 95

EASY

NEET

IMPORTANT

Earn 100

White light is incident normally on a glass slab. Inside the glass slab,

50% studentsanswered this correctly

Important Questions on Ray Optics

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 17 - Ray Optics>Level 2>Q 96

The ratio of the refractive index of red light to that of blue light in air is ______.

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 17 - Ray Optics>Level 2>Q 97

The angle of a prism is $30^{\circ}$ and its refractive index is $\sqrt{2}$ ,Also one of its surface is silvered. The angle of incidence at which a ray be incident on one surface so that it retraces its path after reflection from the silvered surface is

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 17 - Ray Optics>Level 2>Q 98

For a medium, refractive indices for violet, red and yellow are known to be

1.62

,

1.52

and

1.55

respectively. What will be the dispersive power of the medium ?

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 17 - Ray Optics>Level 2>Q 99

Flint glass prism is joined by a crown glass prism to produce dispersion without deviation. The refractive indices of these prisms for mean rays are known to be

1.602

and

1.500

, respectively. Let the angle of prism of flint prism be

10^{\circ}

, then what will be the angle of prism for crown prism ?

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 17 - Ray Optics>Level 2>Q 100

Let the refractive indices of crown glass for red, yellow and violet colours are

1.5140, 1.5170

and

1.5318

respectively and similarly that for flint glass these are

1.6434, 1.6499

and

1.6852

, respectively. Then what are the dispersive powers for crown and flint glass, respectively ?

EASY

NEET

IMPORTANT

Physics Crash Course NEET>Chapter 17 - Ray Optics>Level 2>Q 101

A given ray of light suffers minimum deviation in an equilateral prism $P$ . Additional prisms $Q$ and $R$ of identical shape and of same material as $P$ are now added as shown in the figure. The ray will now suffer

Question Image