11th Physics MCQs Preparation 2022 and Onwards (Unit: Physical Optics: Set-1 (27 MCQs)) for National MDCAT, ECAT, FPSC, PPSC, JOB Exam, Physics Lecturer, SSC, HSSC (F.Sc.), BS, MS Exams NTS, ETS, etc.



1. Who presented the corpuscular theory of light?




... Answer is B. Newton
Newton's presented corpuscular theory of light and Huygen's wave theory


2. Which phenomenon does not explain the wave theory of light?




... Answer is D. Compton effect
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3. Interference of light occurs when the source of light is;




... Answer is D. All of these
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4. In Young's double slit experiment, if the distance between two slits is halved and the distance between slits and screen is doubled then what will be the fringe width?




... Answer is D. Quadrupled
Δy = `\frac {mλ}{d}` = Quadrupled (four times)


5.  In Young's double slit experiment, the ratio of fringe width of bright to dark fringe is;




... Answer is A. 1:1
Bright to dark fringe are equally spaced.


6. In Young's double-slit experiment if white light is used then;




... Answer is A. Bright fringes will be seen
 If white light is used in place of monochromatic light in Young's double slit experiment, then the central fringe will be observed as white and some coloured fringes around the central fringes are formed.


7. When light is reflected from dense medium to rare medium than its path difference :




... Answer is B. Changes by `\[frac {λ}{2}]`
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8. Michelson interferometer is an optical instrument which is being used for the measurement of




... Answer is D. Wavelength
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9. Mathematical condition of destructive interference in the thin film is;




... Answer is C. `\[m + 1/2]` λ
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10. Which parameter of light does not change when light is reflected from dense medium to rare medium?




... Answer is A. Frequency `
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11. In the Michelson interferometer, a fringe is changed by changing the position of the movable mirror at a distance




... Answer is B. `\frac {λ}{2}`
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12. Number of slits in a diffraction grating depends upon.




... Answer is C. Wavelength of light
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13. If the wavelength of the incident X-rays is 2 ｘ 10⁻¹⁰ m then the required number of slits per centimetre for its diffraction should be




... Answer is C. 5 ｘ10⁸
--------d = `\frac {1}{N}`


14.  Which phenomenon has confirmed that light is a transverse wave?




... Answer is D. Polarization
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15. If the unpolarized incident light with an intensity I is polarized by a Polaroid sheet, then the intensity of plane-polarized light will be;




... Answer is A. `\frac {I}{2}`
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16.. Which one of the following cannot be polarized.




... Answer is D. Sound waves
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17. Signal from a remote control to the device operated by it travels with the speed of: :




... Answer is B. Light
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18. Light of wavelength λ is incident normally on a diffraction grating for which the slit spacing is equal to 3λ . What is the sine of the angle between the second-order maximum and the normal? :




... Answer is C. `\ frac {2}{3}`
we have d sinθ = mλ 👉 when d = 3λ and m = 2 ( second order fringes) 👉 3λ sinθ = 2λ 👉 sinθ = `\ frac {2}{3}`


19. Which of the following gives three regions of the electromagnetic, spectrum in order of increasing wavelength, visible radiation




... Answer is C. Ultraviolet, infra-red microwaves
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20. Two monochromatic radiations X and Y are incident normally on a diffraction grating. The second-order intensity maximum for X coincides with the third-order intensity maximum for Y. What is the ratio ( wavelength of X)/(wavelength of Y)




... Answer is B. `\ frac {2}{3}`
Using Formula d sinθ = mλ 👉 For Radiation X d sinθ = m λx -----------eqn (1) 👉 For Radiation y d sinθ = m λy -----------eqn (1) diving eqn (2) by eqn (1) at m=2 for X radiation and m= 3 for Y radiation 👉 `\ frac {λx}{λy}` = `\frac {2}{3}`


21. The principle of Young's double slits experiment is based on the division of:




... Answer is D. Wavefront
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22. Which one of the following properties proves the transverse wave nature of light




... Answer is C. Polarization
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23. Coloured fringes observed in soap bubbles are the examples of




... Answer is B. Interference
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24. During a sunny day we see the objects in a classroom even when all the electric lights are off, due to




... Answer is C. Diffraction of light
The bending of light wave around an obstacle and spreading into its geometrical shadow is called diffraction


25. The principle of the Michelson interferometer is based on the division of




... Answer is B. Amplitude
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26. In Young's double-slit experiment the separation between the slits is halved and the distance between the slits and the screen is doubled. The fringe width is




... Answer is D. Quadrupled
Formula for the width of fringes in Michelson interferometer experiment Δy = `\ frac {λL}{d}` 👉 when d' = `\ frac {d}{2}` and L' = 2 L 👉 Δy' = `\ frac {λ2L}{d/2}` = 4`\ frac {λL}{d}` = 4 Δy


27. The tip of a needle does not give a sharp image. It is due to




... Answer is C. Diffraction
The bending of a light wave around an obstacle and spreading into its geometrical shadow is called diffraction



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Or 

Select from the below Links for HSSC-I (Class-11) :  Physics MCQS Preparation


1. Unit:  Measurements: Set-1 (32 MCQs), Set-2 (50 MCQs), Set-3 (50 MCQs),                                   Set-4 (50 MCQs),   Set-5 (50 MCQs),  

2. Unit:  Vectors and Equilibrium: Set-1 (34 MCQs), 

3. Unit:  Force and Motion: Set-1 (34 MCQs), 

4. Unit:  Work and Energy: Set-1 (29 MCQs), 

5. Unit:  Rotational and Circular Motion: Set-1 (31 MCQs), 

6. Unit:  Fluid Mechanics or Dynamics: Set-1 (31 MCQs), 

7. Unit:  Oscillations : Set-1 (27 MCQs), 

8. Unit:  Waves : Set-1 (27 MCQs), 

9. Unit:  Physical Optics : Set-1 (27 MCQs), 

10. Unit:  Thermodynamics: Set-1 (34 MCQs),  

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