RPSC – Assistant – Conservator – of – Forest – Physics – Paper – 2011
| Sr. No | Questions with multiple options |
| 1. | Which of the following is conserved when light waves interfere?
(a) Mass (b) Energy (c) Intensity (d) Frequency |
| 2. | Colours are produced in a soap bubble by
(a) Interference (b) Dispersion (c) Diffraction (d) Polarization |
| 3. | Two waves having the intensities in the ratio 9 : 1 produce interference. The ratio of maximum to minimum intensity is
(a) 4:1 (b) 4:3 (c) 3:1 (d) 2:1 |
| 4. | What is the nature of the source of light in the biprism interference experiment?
(a) Point source (b) Extended source (c) Narrow slit (d) Multiple source |
| 5. | Two sources of light are said to be coherent when both give out light waves of same
(a) Speed and phase (b) Amplitude and phase (c) Wavelength and constant phase difference (d) Wavelength and intensity |
| 6. | Monochromatic light from a narrow slit illuminates two parallel narrow slits producing an interference pattern on a screen far away. What is the effect on the fringe width if the slit separation is made twice and distance between the screen and slit is reduced to half.
(a) It is doubled (b) It is halved (c) It remains the same (d) It becomes one fourth |
| 7. | The diameter of dark rings in Newtons rings is
(a) Inversely proportional to the square root of odd numbers (b) Directly proportional to the square root of natural numbers (c) Directly proportional to the square root of odd numbers (d) Inversely proportional to the square root of natural numbers |
| 8. | In the Fresnel’s Biprism experiment, the two Coherent sources are obtained by
(a) Refraction (b) Reflection (c) Internal reflection (d) Reflection and refraction both |
| 9. | Two slits illuminated with red light of wavelength 650 nm have a separation of 1mm. The interference fringes are observed on a screen at 1m from the slits. The distance between the third dark fringe and the fifth bright fringe will be:
(a) 0.65 mm (b) 4.88 mm (c) 3.25 mm (d) 1.63 mm |
| 10. | A thin film is observed in white light. The colour of the film seen at a particular point depends on
(a) Thickness of the film (b) Distance of the source (c) Location of the observer (d) Width of source |
| 11. | Which of the following is essential for observing diffraction?
(a) A narrow slit (b) White light (c) Screen (d) Two coherent sources |
| 12. | The condition for observing Fraunhofer diffraction from a single slit is that the light wave front incident on the slit should be
(a) Elliptical (b) Plane (c) Cylindrical (d) Spherical |
| 13. | When white light is incident on a diffraction grating, the light that is deviated most from the central image
(a) Blue (b) Yellow (c) Red (d) Violet |
| 14. | Maximum number of orders available with a grating is
(a) Directly proportional to the grating element. (b) Inversely proportional to the grating element. (c) Independent of the grating element. (d) Directly proportional to the square of grating element. |
| 15. | Which property of light is confirmed by diffraction?
(a) Particle nature (b) Transverse wave nature (c) Longitudinal wave nature (d) Wave nature |
| 16. | Which of the following undergoes largest diffraction
(a) Gamma Rays (b) Ultraviolet light (c) Radio waves (d) Infrared light |
| 17. | In the diffraction pattern due to a single slit, the width of the central maximum will be
(a) Less for narrow slit (b) Greater for narrow slit (c) Greater for wide slit (d) Less for wide slit |
| 18. | The width of the diffraction fringe varies
(a) Inversely as the wavelength (b) Directly as the width of slit (c) Directly as the distance between the slit and screen (d) Inversely as the width of slit |
| 19. | To observe diffraction, the size of the obstacle
(a) Should be of same order as the wavelength (b) Should be much larger than the wavelength (c) Is independent of wavelength (d) Should be half of the wavelength |
| 20. | Dispersine power of a grating can be defined as
(a) Change in angle of reflection with change in wavelength (b) Change in angle of diffraction with respect to change in wavelength (c) Change in angle of refraction with change in wavelength (d) Change in angle of incidence with change in wavelength |
| 21. | The resolving power of a microscope is
(a) Limited by the wavelength of light (b) Limited by the refractive index of the glass of the lens (c) Limited by the diameter of the objective lens (d) Independent of all three |
| 22. | The resolving power of a telescope with lens of diameter 1.22 m for a wavelength of 500 nm is
(a) 200 (b) 2 (c) 2000 (d) 2000000 |
| 23. | The resolution limit of the eye is 1 minute. At a distance of x km from the eye, two persons stand with a lateral separation of 3 m. For the two persons to be just resolved by the naked eye, x should be
(a) 10 km (b) 20 km (c) 15 km (d) 30 km |
| 24. | The criterion of resolution of optical instruments was given by
(a) Chadwick (b) Newton (c) Rayleigh (d) Huygens |
| 25. | The resolving power of a telescope depends on
(a) The focal length of the objective lens (b) Diameter of the objective lens (c) The magnification of the eye-piece (d) Refractive index of the objective lens |
| Data Collected By – K. Jeyanthi | |
| Published On – 15th Dec 2021 | |
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