If the focal length of a camera is 20cm, the distance from the film at which the lens must be set to produce a sharp image of 100cm away is

Assessment: JAMB UTME - Physics - 2018 Subject: Physics

Question 1 Report

17cm

20cm

25cm

100cm

Answer Details

F = 20cm
V = 100cm
U = ?

\frac{1}{U}

+

\frac{1}{V}

=

\frac{1}{F}

\frac{1}{20}

+

\frac{1}{100}

=

\frac{1}{F}

\frac{5 + 1}{100}

=

\frac{1}{F}

F =

\frac{100}{6}

= 16.7cm
= 17cm

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