FSC Physics MCQs Chapter 9 Class 11

Created on February 07, 2022

Physics Ch 9 Class 11 PHYSICAL OPTICS

1 / 42

The phenomenon by which light travels in an optical fibres is:

NUMS 2016
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Reflection

B) Refraction

C) Total internal reflection

D) Transmission

2 / 42

Two glass prisms Pl and P2 are to be combined together to produce dispersion without deviation. The angle of the prisms P1 and P2 are selected as 40 and 30 respectively. If the refractive index of prism Pl is 1.54, then that of P2 will be:

NUMS 2014
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) 1.48

B) 1.58

C) 1.62

D) 1.72

3 / 42

In interference energy destroyed

May be

Will be

Can be

Cannot be

4 / 42

Incident rays of light parallel to the principal axis of a convex lens, after refraction by the lens, will:

NTS 2017
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) converge at the principal focus

B) converge inside the principal focus

C) converge outside the principal focus

D) converge at the center of curvature

5 / 42

When light enters from air to glass remains constant?

Frequency

Wavelength

Velocity

All of these

6 / 42

Confining of wave into one plane is called

Polarization

Depolarization

Transformation

None of these

7 / 42

A mixture of electric fields and magnetic fields is?

Plane polarized light

Circular polarized light

Unpolarized light

Constant

8 / 42

In an astronomical telescope, the lens called eyepiece forms an image of a distant object that is:

NTS 2016 SMBBMC
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Real and diminished

B) Real and magnified

C) Virtual and diminished

D) Virtual and magnified

9 / 42

If an Electromagnetic wave is plane polarized, then the direction of electric field and magnetic field will be

Perpendicular

Parallel

Along direction of propagation of wave

None of these

10 / 42

What will be the position of the object, when a convex lens of focal length 20 cm, is used to form an erect image which is twice as large as the object?

NTS 2016 DUHS & JSMU
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

B) The object is 4 cm from the lens

C) The object is 6 cm from the lens

D) The object is 8 cm from the lens

E) The object is 10 cm from the lens

11 / 42

How can we define linear magnification produced by a lens?

NTS 2015 SMBBMC
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) The ratio of the object distance to the image distance

B) The ratio of the image distance to the focal length

C) the ratio of the size of the object to the size of the image

D) the ratio of the size of the image to the size of the object

12 / 42

Light rays coming from the tube light are

Plane

Spherical

Cylindrical

None

13 / 42

Interference is shown by Light

Monochromatic

Polychromatic

Both a and b

None of these

14 / 42

mλ=2dsin(θ) this relation is called as

NTS 2015 DUHS and JSMU
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Coulomb’s Law

B) Bragg’s Law

C) Faraday’s Law

D) Ohm’s Law

15 / 42

Which of the following can be the objective of Polarization:

Decrease in E

Decrease in capacitance

Decrease in current

None of these

16 / 42

Sky appears blue due to?

Light Interference

Light diffraction

Light scattering

Light polarization

17 / 42

Length of the telescope is:

NTS 2015 SMBBMC
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) The distance between the objective and focal point of eyepiece

B) the distance between the object and final image

C) the distance between the objective and eyepiece

D) the distance between the focal point of objective and eyepiece

18 / 42

A microscope has an objective of 10 mm focal length and an eye piece of 25 mm focal length. What is the distance between the lenses, if the object is in sharp focus when it is 10.5 mm from the objective?

NTS 2014
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) 115 mm

B) 235 mm

C) 417 mm

D) 716 mm

19 / 42

Wave fronts coming from small light bulb

Spherical

Cylindrical

Plane

None

20 / 42

A real image formed by convex lenses is always:

NUMS 2016
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Erect

B) Inverted

C) Magnified

D) Diminished

21 / 42

The range of wavelengths for visible light is between _______.

NTS 2016 SMBBMC
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) 4.6 x 107 to 7.8 x 10 -7 m

B) 4.0 x 10 -7 to 7.6 x 10 -7 m

C) 4.0 x 10 -6 to 7.6 x 10 -6 m

D) 4.0 x 10 -8 to 7.6 x 10 -8 m

22 / 42

The phenomenon by which light travels in an optical fibres is:

NUMS 2016
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Reflection

B) Refraction

C) Total internal reflection

D) Transmission

23 / 42

Formation of colours in a thin film of oil is due to:

NTS 2015 SMBBMC
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Diffraction of light waves

B) Dispersion of light waves

C) interference of light waves

D) scattering of light waves

24 / 42

When a certain metal surface is illuminated with light of frequency v. the stopping potential for photoelectric current is V0. When the same surface is illuminated by light of frequency V/2, the stopping potential is VO-/4. The threshold frequency for photoelectric emission is:

NUMS 2014
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) V/6

B) V/3

D) 4V/3

C) 2V/3

25 / 42

Which photon carries the most energy?

PMC 2020
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Blue

B) Violet

C) Red

D) Green

26 / 42

The linear magnification produced by a lens is defined as the ratio of the:

I. Size of the image to the size of object

II. Size of the lens to the size of object

III. Size of the lens to the size of the image

NTS 2013
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) I only

B) II only

C) III only

D) II and III only

27 / 42

In Young’s Experiment, the central spot In Interference pattern is

Always bright

Always dark (

Depends on distance from screen

Depends on size of slit

28 / 42

Light can be polarized by:

reflection
double refraction
scattering of light
NTS 2017
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

B) II only

C) III only

D) I and II only

E) I, II and III

29 / 42

The branch of Physics in which we study the properties of light and its applications on optical instruments is called?

Physical Optics

Quantum optics

Light optics

None of these

30 / 42

In an astronomical telescope, the distance between the objective and eyepiece is called:

NTS 2013
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Magnifying Power of the telescope

B) Width of the telescope

C) Length of the telescope

D) Height of the telescope

31 / 42

When a certain metal surface is illuminated with light of frequency v. the stopping potential for photoelectric current is V0. When the same surface is illuminated by light of frequency V/2, the stopping potential is VO-/4. The threshold frequency for photoelectric emission is:

NUMS 2014
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) V/6

B) V/3

D) 4V/3

C) 2V/3

32 / 42

A microscope has an objective of 10 mm focal length and eyepiece of 25 mm focal length. What is the distance between the lenses if the object is in sharp focus when it is 10.5 mm from the objective?

NTS 2015 DUHS and JSMU
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) 232.7 mm

B) 431.1 mm

C) 511.9 mm

D) 711.8 mm

33 / 42

The distance between two fringes in double slit experiment is directly proportional to

Wavelength of light

Distance between the slits

Both a and b

None of these

34 / 42

An object placed in front of a concave mirror at a distance of X cm from the pole gives a 3 times magnified real image. If it is moved a distance of X+5cm, the magnification of the image becomes 2. The focal length of the mirror is:

NUMS 2014
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) 15cm

B) 20cm

C) 25cm

D) 30cm

35 / 42

A parallel beam of white light is incident normally on a diffraction grating. It is noted that the second-order and third-order spectra partially overlap. Which wavelength in the third-order spectrum appears at the same angle as the wavelength of 600 nm in the second-order spectrum?

NTS 2013
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) 300 nm

B) 400 nm

C) 600 nm

D) 900 nm

36 / 42

A 4 cm high object is located 10 cm from the converging lens, whose focal length is 20 cm. The image so formed will be:

NTS 2013
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

B) Erect

C) Real

D) Inverted

E) Both Virtual and Erect

37 / 42

.Light can be polarized by which of the following methods?

I. scattering of light

II. double refraction

III. reflection

NTS 2014
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

B) II only

C) III only

D) I and III only

E) I, II, and III

38 / 42

The main difference between X rays and Y rays is:

PMC 2020
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Frequency

B) Wave length

C) Energy

D) Origin

39 / 42

In an experiment, an object was placed on the principal axis of a convex lens 25 centimetres away from the lens. A real image 4 times the size of the object was obtained. The focal length of the lens is:

NTS 2017
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) 20 cm

B) 25 cm

C) 33 cm

D) 50 cm

40 / 42

The central fringe in a diffraction pattern obtained by using a single slit is?

Bright

Dark

No fringes will be formed

None of the above

41 / 42

Which of the following series lies in the ultraviolet range:

PMC 2020
Physics
Optics, Nature of Light and Optical Instruments
Elimination Tool:

A) Balmer series

B) Pashcher series

C) Lyman series

D) Brackett series

42 / 42

If the grating element is made 1/10th the resolving power will become

1/100 times

1/10 times

100 times

10 times

Your score is

The average score is 54%

0%

Learn Anytime Anywhere

PakLearningSpot