A shaving mirror is advertised as producing an upright image twice the height of a…
PHYSICS · Multi-part · CBSE · Physics · Light — Reflection and Refraction · Light — Reflection and Refraction
Problem
A shaving mirror is advertised as producing an upright image twice the height of a person’s face when the face is positioned 20 cm from the mirror along the principal axis. The mirror is known to be concave.
Assume that the face is 18 cm tall and can be treated as a vertical arrow object.
(a) Draw a to-scale ray diagram on your answer sheet that models the situation described. Clearly label the focal point and the centre of curvature produced by your scale.
(b) Using measurements from your diagram, estimate the focal length of the mirror and the distance between the mirror and the image. State the scale you used and show your working.
(c) The manufacturer claims the image is exactly twice life-size. Using appropriate quantitative relationships, calculate the theoretical magnification and comment on whether your diagram supports the manufacturer’s claim.