Optical Instruments — NEET Physics practice

Question 1

A giant refracting telescope has an objective of focal length 19 m and an eyepiece of focal length 1.0 cm. In normal adjustment it is used to view the Moon. What is the diameter of the Moon's image formed by the objective? (Diameter of Moon = 3.5 × 10⁶ m, radius of lunar orbit = 3.8 × 10⁸ m)

Accepted Answer

17.5 cm

Answer

10 cm

Answer

12.5 cm

Answer

15 cm

Question 2

Read Statement A and Statement B carefully and choose the correct option. Statement A: The magnifying power of an astronomical telescope in normal adjustment is the ratio of the focal length of the objective to that of the eyepiece. Statement B: An astronomical telescope has a large-aperture objective to collect more light and give a brighter image.

Accepted Answer

Both Statement A and Statement B are true.

Answer

Statement A is true, but Statement B is false.

Answer

Statement A is false, but Statement B is true.

Answer

Both Statement A and Statement B are false.

Question 3

Read Statement A and Statement B carefully and choose the correct option. Statement A: An astronomical telescope provides angular magnification of distant objects. Statement B: The objective of an astronomical telescope has a shorter focal length than the eyepiece.

Accepted Answer

Statement A is true, but Statement B is false.

Answer

Both Statement A and Statement B are true.

Answer

Statement A is false, but Statement B is true.

Answer

Both Statement A and Statement B are false.

Question 4

Read Statement A and Statement B carefully and choose the correct option. Statement A: The eyepiece of a telescope is used to view the real image formed by the objective at its focus. Statement B: In a refracting (astronomical) telescope, the objective and eyepiece are both convex lenses.

Accepted Answer

Both Statement A and Statement B are true.

Answer

Statement A is true, but Statement B is false.

Answer

Statement A is false, but Statement B is true.

Answer

Both Statement A and Statement B are false.

Question 5

Match the concepts related to optical instruments (Column I) with their descriptions (Column II). Column I: Magnification by a lens; Mirror equation; Convex lens as a converging lens; Prism in optical instruments Column II: Uses total internal reflection to redirect light; Focal length is positive; Relates object distance, image distance and focal length; Ratio of image height to object height

Accepted Answer

A→S, B→R, C→Q, D→P

Answer

A→R, B→S, C→P, D→Q

Answer

A→Q, B→R, C→S, D→P

Answer

A→S, B→P, C→Q, D→R

Optical Instruments: NEET practice questions

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More Physics topics

Reflection & Spherical Mirrors

Refraction & Total Internal Reflection

Lenses & Lens Maker's Formula

Prism, Dispersion & Scattering