JAMB Physics questions: Optical instruments

12 questions with answers and explanations. Tap an option to check yourself.

1. Question 1· Optical instruments· JAMB

   Short sight is corrected with

   • Aa converging (convex) lens
   • Ba diverging (concave) lens
   • Ca plane glass
   • Da cylindrical mirror

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   Explanation and discussion

2. Question 2· Optical instruments· JAMB

   Long sight is corrected using

   • Aa prism
   • Ba diverging (concave) lens
   • Ca plane mirror
   • Da converging (convex) lens

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   Explanation and discussion

3. Question 3· Optical instruments· JAMB

   An object is 15 cm from a converging lens of focal length 10 cm. Find the image distance.

   • A25 cm
   • B6 cm
   • C30 cm
   • D5 cm

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   Explanation and discussion

4. Question 4· Optical instruments· JAMB

   The image formed on the film or sensor of a camera is

   • Areal, upright and magnified
   • Bvirtual, upright and magnified
   • Creal, inverted and diminished
   • Dvirtual, inverted and diminished

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5. Question 5· Optical instruments· JAMB

   The final image seen through an astronomical telescope in normal adjustment is

   • Ainverted
   • Bupright and diminished
   • Creal
   • Dthe same size as the object

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6. Question 6· Optical instruments· JAMB

   The final image formed by a compound microscope is

   • Areal, upright and diminished
   • Bvirtual, inverted and magnified
   • Cvirtual, upright and diminished
   • Dreal, inverted and the same size

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   Explanation and discussion

7. Question 7· Optical instruments· JAMB

   A diverging lens has a focal length of 50 cm. Its power is

   • A+50 D
   • B+2 D
   • C−0.02 D
   • D−2 D

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8. Question 8· Optical instruments· JAMB

   In the camera, the part that controls the amount of light entering, like the iris of the eye, is the

   • Alens
   • Bfilm
   • Cdiaphragm (aperture)
   • Dshutter button

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9. Question 9· Optical instruments· JAMB

   Find the power of a converging lens of focal length 25 cm.

   • A+0.25 D
   • B+25 D
   • C+4 D
   • D−4 D

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10. Question 10· Optical instruments· JAMB

    Long sight (hypermetropia) is corrected with

    • Aa converging lens
    • Ba diverging lens
    • Ca plane mirror
    • Da prism

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    Explanation and discussion

11. Question 11· Optical instruments· JAMB

    To use a converging lens as a magnifying glass, the object must be placed

    • Aat 2F
    • Bbetween the lens and its principal focus
    • Cbeyond 2F
    • Dat infinity

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12. Question 12· Optical instruments· JAMB

    An object is placed 60 cm from a converging lens of focal length 20 cm. Find the image distance.

    • A40 cm
    • B15 cm
    • C30 cm
    • D60 cm

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    Explanation and discussion