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NEET-UG and JEE Main Physics · Class 12

Magnification, power of a lens and lenses in contact — NEET & JEE Questions

Magnification, power of a lens and lenses in contact is a topic in Optics, a Class 12 Physics chapter of the NEET-UG and JEE Main syllabus. TestBudy holds 14 published NEET-UG and JEE Main questions on Magnification, power of a lens and lenses in contact, each with the marking scheme of the real paper.

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Magnification, power of a lens and lenses in contact MCQs with solutions

10 of the 14 published questions on this topic, exactly as they appear in a test. Answers and worked solutions come with your result rather than on this page.

  1. Question 1 · difficulty L1 · recall

    The power of a thin lens in dioptres is

    • A. P=f in metres
    • B. P=1/f²
    • C. P=1/f with f in metres
    • D. P=f/100

  2. Question 2 · difficulty L1 · understanding

    A concave lens in air has

    • A. positive power
    • B. zero power always
    • C. power unrelated to focal length sign
    • D. negative power

  3. Question 3 · difficulty L2 · understanding

    For two thin lenses in contact, the equivalent power is

    • A. P=P1+P2
    • B. P=P1P2
    • C. P=P1-P2 always
    • D. 1/P=P1+P2

  4. Question 4 · difficulty L2 · application

    A +4 D lens and a -1 D lens are placed in contact. Their combined power is

    • A. +5 D
    • B. +3 D
    • C. -3 D
    • D. +4 D

  5. Question 5 · difficulty L2 · understanding

    The power P of a thin lens of focal length f in metres is

    • A. P=1/fP=1/f
    • B. P=fP=f
    • C. P=f2P=f^2
    • D. P=−fP=-f always

  6. Question 6 · difficulty L3 · application

    The focal length of a +2 D lens is

    • A. 2.0 m
    • B. 0.20 m
    • C. 0.50 m
    • D. -0.50 m

  7. Question 7 · difficulty L3 · application

    A lens forms a real inverted image three times the object height. Its linear magnification is

    • A. +3
    • B. -1/3
    • C. +1/3
    • D. -3

  8. Question 8 · difficulty L3 · application

    A converging lens has focal length 0.50 m. What is its power?

    • A. +2 D
    • B. +0.5 D
    • C. -2 D
    • D. +5 D

  9. Question 9 · difficulty L3 · application

    Two thin lenses of powers +3 D and -1 D are in contact. What is the equivalent power?

    • A. +2 D
    • B. +4 D
    • C. -3 D
    • D. -2 D

  10. Question 10 · difficulty L4 · analysis

    Two +5 D thin lenses in contact have equivalent focal length

    • A. 0.10 m
    • B. 0.20 m
    • C. 0.40 m
    • D. 1.0 m

Common mistakes in Magnification, power of a lens and lenses in contact

Recorded against questions in this topic that are not shown above, so none of these points at an answer you can see on this page.

  • Uses only image size and ignores the sign convention for inversion.

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