# Ray Optics (KVPY (Kishore Vaigyanik Protsahan Yojana) Stream-SA (Class 11) Physics): Questions 20 - 24 of 26

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## Question number: 20

» Ray Optics » Lens Maker's Formula and Lens Formula

MCQ▾

### Question

A point source of light is moving at a rate of 2 cm-s–1 towards a thin convex lens of focal length 10 cm along its optical axis. When the source is 15 cm away from the lens the image is moving at

### Choices

Choice (4) Response

a.

8 cm-s–1 away from the lens

b.

4 cm-s–1 away from the lens

c.

4 cm-s–1 towards the lens

d.

8 cm-s–1 towards the lens

## Question number: 21

» Ray Optics » Mirror Formula

MCQ▾

### Question

In a concave mirror, an object is placed at a distance 12 cm from the focus and its image is formed at a distance 3 cm from the focus. The focal length of the mirror is,

### Choices

Choice (4) Response

a.

4 cm

b.

5 cm

c.

6 cm

d.

3 cm

## Question number: 22

» Ray Optics » Power of a Lens

MCQ▾

### Question

A convex lens of focal length 21 cm and a concave lens of focal length 17 cm are placed in close contact with one another. The power of the combination is –

### Choices

Choice (4) Response

a.

2.43 D

b.

-2.43 D

c.

0.41 D

d.

-1.12 D

## Question number: 23

» Ray Optics » Mirror Formula

MCQ▾

### Question

In a concave mirror, an object is placed at a distance 25 cm from the focus and its image is formed at a distance 4 cm from the focus. The focal length of the mirror is,

### Choices

Choice (4) Response

a.

15 cm

b.

20 cm

c.

10 cm

d.

5 cm

## Question number: 24

» Ray Optics » Magnification

MCQ▾

### Question

An object of height 2.5 cm is placed at a distance of 10 cm in front of a concave lens of power, – 12 diopters. The height of the image is –

### Choices

Choice (4) Response

a.

2.46

b.

1.46

c.

1.13

d.

2.13

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