Department of Natural Sciences

Clayton College & State University

November 12, 2003

Physics 1112 – Quiz 9

Name ___SOLUTION________________________________

1. A 500- nm light wave propagating in vacuum impinges normally on a glass sheet of index of refraction n = 1.600. How many waves span the glass if it is 1.00 cm thick?

l = l₀/n

l = (500 nm)/(1.60) = 312.5 nm

# = (1.00 x 10 ^–2 m)/(312.5 x 10^-9 m) = 32 000

2. A beam of light impinges on an air-liquid interface at an angle of 55^o. The refracted ray is observed to be transmitted at 40^o. What is the index of refraction of the liquid?

n₁ sin (q₁) = n₂ sin (q₂)

1.00 sin (55^o) = n₂ sin (40^o)

n₂ = sin (55^o)/sin (40^o)

n₂ = 1.27