JAMB - Physics (1986 - No. 23)
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
5.3cm
3.2cm
2.7cm
1.6cm
Explication
v = 4u, if u = 2cm, v = 8cm
F = \(\frac{uv}{u + v}\)
= \(\frac{2 \times 8}{2 + 8}\)
= 1.6cm
r = 2F
= 2 x 1.6
= 3.2cm
F = \(\frac{uv}{u + v}\)
= \(\frac{2 \times 8}{2 + 8}\)
= 1.6cm
r = 2F
= 2 x 1.6
= 3.2cm