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NEET2026PhysicsChapterActual

An amateur astronomer constructs an astronomical refracting telescope using two convex lenses of focal lengths 100 cm and 4 cm . The telescope is used to observe the moon in normal adjustment. Consider the following statements regarding this telescope: (I) The distance between the objective lens and the eyepiece is 1.04 m . (II) The magnification of the telescope is +25 . (III) The final image of the moon formed by t

Options

  1. A(I), (II) and (III)
  2. B(II), (III) and (IV)
  3. C(I), (III) and (IV)
  4. D(I), (II) and (IV)

Correct answer

C. (I), (III) and (IV)

Step-by-step solution

For an astronomical telescope in normal adjustment, the distance between the objective lens and the eyepiece (tube length) is given by L = f_o + f_e . Given f_o = 100 cm and f_e = 4 cm , we have L = 100 + 4 = 104 cm = 1.04 m . Thus, statement (I) is correct. The magnifying power of the telescope in normal adjustment is m = - f_o f_e = - 100 4 = -25 . The negative sign indicates that the final image is inverted. Statement (II) claims the magnification is +25 , which is incorrect. In an astronomical telescope, the ob

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