# Ray Optics (KVPY (Kishore Vaigyanik Protsahan Yojana) Stream SB-SX (Class 12 & 1st Year B.Sc.) Physics): Questions 9 - 11 of 13

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## Question number: 9

» Ray Optics » Snell's Law

Appeared in Year: 2015

MCQ▾

### Question

Electromagnetic waves emanating from a point A (in air) are incident on a rectangular block of material M and emerge from the other side as shown. The angles i and r are angles of incidence and refraction when the wave travels from air to the medium. Such paths for the rays are possible

### Choices

Choice (4) Response

a.

only with gamma rays with a wavelength smaller than atomic nuclei of the material

b.

If the material has a refractive index less than zero

c.

If the material has a refractive index very nearly equal to zero

d.

only if the wave travels in M with a speed faster than the speed of light in vacuum.

## Question number: 10

» Ray Optics » Reflection and Refraction of Light » Spherical Surface

Appeared in Year: 2014

MCQ▾

### Question

A concave mirror of radius of curvature R has a circular outline of radius r. A circular disc is to be placed normal to the axis at the focus so that it collects all the light that is reflected from the mirror from a beam parallel to the axis. For r < < R, the area of this disc has to be at least,

### Choices

Choice (4) Response

a.

b.

c.

d.

## Question number: 11

» Ray Optics » Snell's Law

Appeared in Year: 2015

MCQ▾

### Question

A cubical vessel has opaque walls. An observer (dark circle in figure below) is located such that she can see only the all CD but not the bottom. Nearly to what height should water be poured so that she can see an object placed at the bottom at a distance of 10 cm from the corner C? Refractive index of water is 1.33.

### Choices

Choice (4) Response

a.

10 cm

b.

45 cm

c.

27 cm

d.

16 cm

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