Free NEET Physics multiple-choice questions on Optical Instruments. Attempt each question and reveal the answer with a full explanation.
The magnifying power of a simple microscope when the image is formed at the least distance of distinct vision D is: 1 + D/f D/f 1 - D/f f/D The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 Å is of the order of: 10 -6 rad 10 -2 rad 10 -4 rad 10 -8 rad If the focal length of objective lens is increased then magnifying power of: Microscope will decrease but that of telescope will increase Microscope and telescope both will increase Microscope and telescope both will decrease Microscope will increase but that of telescope will decrease If the wavelength of light used in a microscope is doubled and the numerical aperture is halved, the resolving power of the microscope will: Become one-fourth Remain unchanged Be doubled Be quadrupled For a normal eye, the limit of resolution is nearly: 1' (one minute) 1'' (one second) 1 (one degree) 0.1' The limit of resolution of a telescope with an objective of diameter 2 m for light of wavelength 500 nm is approximately: 0.3 10 -6 rad 1.2 10 -6 rad 0.6 10 -6 rad 2.4 10 -6 rad A hypermetropic person has a near point of 100 cm . What is the power of the lens required to read a book at 25 cm ? +3.0 D -3.0 D +4.0 D -4.0 D The tube length of a compound microscope is the distance between: The second focal point of objective and first focal point of eyepiece The objective and eyepiece The object and objective The eye and eyepiece A telescope has an objective lens of focal length 150 cm and an eyepiece of focal length 5 cm . If a 50 m tall tower at a distance of 1 km is observed through this telescope in normal adjustment, the angle subtended by the image as seen by the eyepiece is: 1.5 o 3.0 o 0.5 o 0.15 o The ratio of the resolving power of an optical microscope for two wavelengths λ 1 = 4000 Å and λ 2 = 6000 Å is: 3:2 2:3 9:4 16:81 For a compound microscope, the focal lengths of objective and eye-piece are f o and f e . The microscope is focused on an object at distance u o from objective. The magnification is: (v o/u o)(1 + D/f e) (v o/u o)(D/f e) (f o/u o)(1 + D/f e) (v o/u o)(f e/D) In a telescope, the objective lens has a focal length of 144 cm and an eyepiece has a focal length of 6 cm . The magnifying power of the telescope for relaxed eye is: 24 150 138 864 The ratio of resolving powers of an optical telescope for two wavelengths 1 = 4000 and 2 = 6000 is: 3:2 2:3 9:4 4:9 An astronomical telescope has an angular magnification of magnitude 5 for distant objects. The separation between the objective and the eyepiece is 36 cm and the final image is formed at infinity. The focal length f o of the objective and f e of the eyepiece are: 30 cm, 6 cm 45 cm, 9 cm 20 cm, 4 cm 50 cm, 10 cm A person cannot see objects clearly beyond 2.0 m . The power of the lens required to correct this vision is: -0.5 D +0.5 D -2.0 D +2.0 D The magnifying power of a compound microscope can be increased by: Decreasing focal length of objective and eyepiece Increasing focal length of objective and eyepiece Increasing focal length of objective and decreasing eyepiece Decreasing focal length of objective and increasing eyepiece The objective of a telescope has a large focal length and a large aperture in order to: Increase both resolving power and magnification Increase magnification only Increase resolving power only Decrease astronomical aberrations