# NCERT Class 12/MCQ Questions for Class 12 Physics Chapter 9 Ray Optics and Optical Instruments Sample Test,Sample questions

1.1âˆš3

2.âˆš3

3.1/3

4.3

## Question: `A blue cross on the white background is illuminated with white light and is observed through red filter. What is seen?`

1.A red cross on a black background

2.A blue cross on a red background

3.A red cross on a blue background

4. A black cross on a red background

1. 3D

2.1D

3.4D

4.2D

## Question: `A convergent lens will become less convergent in :`

1.oil

2.water

3.both of (a) and (b)

4.None of the above

## Question: `A convex lens is dipped in a liquid, whose R.I. is equal to that of R.I. of material of the lens. Then its focal length will:`

1. become zero

2.become infinite

3.reduce

4.increase

## Question: `A double convex air bubble in water behaves as:`

1. Convergent lens

2.divergent lens

3.plane slab

4.concave mirror

1. 2 cm

2. 4 cm

3.6 cm

4.12 cm

1. Ï€/2

2.Ï€/4

3.Ï€

4.Zero

1.5 mm

2.5 cm

3.0.5 m

4.5 m

1.-2.5 D

2.25 D

3.-ID

4. 0.625 D

1. 40 D

2.-4 D

3.-2.5 D

4.-0.25 diopter

1.10 ms-1

2. 5 ms-1

3.20 ms-1

4.15 ms-1

1. Ï€

2.Ï€/2

3.Ï€/4

4.2Ï€

1.light

2.sound

3.ultrasonics

4.supersonics

## Question: ```The air bubble inside water shine due to: ```

1.Reflection

2.Refraction

3. T.l.R.

4.None of the above

1.violet

2.red

3.orange

4.yellow

## Question: `The angle of minimum deviation for an equilateral glass prism is 30Â°. Refractive index of the prism is:`

1. 1âˆš3

2.âˆš2

3.1

4.canâ€™t be determined

## Question: `The branch of optics dealing with the formation of images using the concept of straight line propagation of light is called:`

1.geometrical optics

2. physical optics

3. corpuscular optics

4.quantum optics

1.Ï€/4

2.Ï€/2

3.Ï€

4.Zero

1.8/9

2.9/8

3.7/6

4.2

1.0Â°

2.30Â°

3.45Â°

4.60Â°

1.-10 cm

2.-20 cm

3.+10 cm

4.None

1. n

2.2n

3.Ï€/2

4.zero

1.45 D

2.9 D

3.19 D

4. 6 D

## Question: `When a beam of light is used to determine the position of an object, the maximum accuracy is achieved if the light is :`

1.polarized

2. of longer Î»

3.of shorter Î»

4.of high intensity

## Question: `When a ray of light (white) enters a lens, undergoes a change is:`

1.wavelength

2.velocity

3.frequency

4.both velocity and wavelength

## Question: `When light travels from one medium to another, which of the following does not change?`

1. frequency

2.refractive index

3.velocity

4.wavelength

## Question: `Which of the following cannot be polarised?`

2.transverse waves

3.sound waves

4.X rays

## Question: `Which of the following is not essential for the formation of a pure spectrum?`

1.parallel beam of light

2.narrow beam of light

3.screen

4.prism in the minimum deviation position

## Question: `Which of-the following is not a property of light?`

1.It can travel through vacuum

2.It has a finite speed

3.It requires a material medium for its propagation

4.It involve transportation energy

## Question: `Which produces additional luminiscence in a fluorescent tube?`

1. infra red rays

2.ultraviolet rays

3.micro waves