Ray Optics and Optical Instruments: NEET questions with solutions

NEET tests mirror and lens formulae with the Cartesian sign convention, apparent depth, critical angle, the lensmaker's formula (including a lens in a liquid), lens combinations, prism minimum deviation, and the microscope and telescope. Most lost marks come from sign errors, from mixing the mirror and lens formulae, and from using approximate formulas outside their range.

1. 1.An object is placed on the principal axis 30 cm in front of a concave mirror of focal length 20 cm. Using the Cartesian sign convention…Reflection of light by spherical mirrorsEasySingle correct
2. 2.Light travels at 2.0 × 10⁸ m s⁻¹ in a certain transparent solid and at 3.0 × 10⁸ m s⁻¹ in air. What is the critical angle for light going…Total internal reflectionEasySingle correct
3. 3.A thin converging lens of focal length 25 cm is placed in contact with a thin diverging lens of focal length 40 cm (both focal lengths given…Power of a lens and combination of thin lenses in contactEasySingle correct
4. 4.A coin lies at the bottom of a tank. The tank holds a 24 cm deep layer of water (refractive index 4/3), and on top of the water floats a 15…Refraction: apparent depthMediumSingle correct
5. 5.A thin biconvex lens of glass (refractive index 1.50) has radii of curvature 20 cm and 30 cm for its two faces. Its focal length in air is…Refraction by a lens: lensmaker's formulaMediumSingle correct
6. 6.A glass prism has a refracting angle of 60°. For monochromatic light, the angle of minimum deviation is measured to be 38°. What is the…Refraction through a prismMediumSingle correct
7. 7.Consider the following statements about a refracting astronomical telescope used in normal adjustment (final image at infinity). Which of…Optical instruments: telescopeMediumStatement based
8. 8.A compound microscope has an objective of focal length 1.0 cm and an eyepiece of focal length 4.0 cm. An object is placed 1.2 cm in front of…Optical instruments: compound microscopeHardSingle correct
9. 9.A thin converging lens L₁ of focal length 20 cm and a thin diverging lens L₂ of focal length 30 cm (magnitude) are placed coaxially 40 cm…Refraction by lenses: image by successive lensesHardSingle correct