Home Technical Mathematics Languages Science Social Science Art Literature Arabic Islamic Studies C.R.K History MusicVisual Art Clothing/Textile Home Management Shorthand
 Physics Paper 2, Nov/Dec. 2009
 Questions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Main
Weakness/Remedies
Strength

Question 3
Part I:      Candidates were required to answer any five questions from this part.
1. A ray of lights is incident on an air-glass boundary at an angle θ.  If the angle between the partially reflected ray and the refracted ray is 90o, calculate angle θ given that the refractive index of glass is 1.54.

_____________________________________________________________________________________________________
Observation

Few candidates attempted this question and majority of those who did performed poorly.  Many candidates misconstrued the question and were calculating critical angle.

Diagram

n  =  sin θ                    =    sin θ    =  tan θ
Sin (90 – θ)                  cos θ

1.54   =   tan θ
θ   =    57o