Optics
Answers
Unit 52: Reflection & Refraction
Q52.1) θ = 30°, and ϕ = 22°.
Q52.2) θ = 25.5°
Q52.3) θ = 48.2°
Q52.4) 5.4 m
Unit 53: Spherical Refractive Surfaces & Lenses
Q53.1) a) 10 cm
b) 10 D
c) 15cm from the lens, opposite the object.
Q53.2) a) 33.3cm from the lens, opposite the object.
b) Real
c) 0.67 cm
d) Inverted
Q53.3) a) 14.3cm from the lens, on the same side as the object.
b) Virtual
c) 0.29 cm
d) Upright
Q53.4) a) 50cm from the biconcave lens, towards your eye.
b) Real
c) 4 cm
d) Inverted
Unit 54: Vision Defects and their Correction
Q54.1) 25 cm
Q54.2) Infinity (there is no distance for which the building will blur)
Q54.3) a) Myopic
b) -0.5 D
Q54.4) a) Hyperopic
b) 2.75 D
Q54.5) No you won’t be successful. Lenses that correct myopia always have negative powers, which means they diverge light rather than focus it to a point.