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Wednesday, 20 May 2026
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Physics Past Questions and Answers

Jamb 1986 Physics Questions

Question 21:
A lens of focal length 12.0cm forms an upright image three times the size of a real object. The distance between the object and the images is
  • A 8.0cm
  • B 16.0cm
  • C 24.0cm
  • D 32.0cm
View Answer & Explanation
Question 22:
In which of the following arrangements is the wavelength in an increasing order?
  • A Gamma rays, infra-red rays, x-rays, radiowaves
  • B Gamma rays, x-rays, infra-red ray, radiowaves
  • C Radiowaves, x-rays, gamma ray, infra-red rays
  • D Infra-red rays, radiowaves, x-rays, gamma rays
View Answer & Explanation
Question 23:
If the refractive index of glass is 1.5, what is the critical angle at the air-glass interface?
  • A Sin<sup style='font-size: smaller;'>-1</sup>\(\frac{1}{2}\)
  • B Sin<sup style='font-size: smaller;'>-1</sup>\(\frac{2}{3}\)
  • C Sin<sup style='font-size: smaller;'>-1</sup>\(\frac{3}{4}\)
  • D Sin<sup style='font-size: smaller;'>-1</sup>\(\frac{8}{9}\)
View Answer & Explanation
Question 24:
A dentist obtains a linear magnification of 4 of a hole in a tooth by placing a concave mirror at a distance, of 2.0cm from the tooth. The radius of Curvature of the mirror is
  • A 5.3cm
  • B 3.2cm
  • C 2.7cm
  • D 1.6cm
View Answer & Explanation
Question 25:
What is the effect of the increase in the size of the hole of a pin-hole camera on the image? it
  • A Gives a blurred image
  • B Corrects for chromatic aberration
  • C Magnifies the image
  • D Brings the image into a sharper focus
View Answer & Explanation