The velocities of light in air and glass are 3.0 x 10\(^8\)ms\(^{-1}\) and 2.0 x 10\(^8\)ms\(^{-1}\) respectively. If the angle of refraction is 30º, the sine of the angle of incidence is?
A
0.33
B
0.50
C
0.67
D
0.75
Verified Correct Answer: D.
Physical Principles & Numerical Solution
\(\frac{\text {sin i}}{\text {sin r}}\) = \(\frac{\text {velocity in air}}{\text {velocity in glass}}\)
\(\frac{\text {sin i}}{\text {sin 30}}\) = \(\frac{3 \times 10^{8}}{2 \times 10^{8}}\)
Sin i = \(\frac{3}{4}\) = 0.75
Source: WAEC / JAMB / NECO Classroom Archive (Record #60827)