13 Top Full: Jawapan Buku Teks Fizik Tingkatan 4 Kssm Aktiviti

Image height = m × object height = 2 × 2 cm =

Real, inverted, magnified. Section E: Optical Instruments (Aktiviti 13.5 – Periscope) Question: Draw a labelled diagram of a periscope using two prisms. Explain how total internal reflection helps in image formation.

Diamond has a high refractive index (2.42) and a low critical angle (24.4°). Light entering diamond undergoes multiple total internal reflections before exiting, creating a sparkling effect. Glass has a lower refractive index (~1.5) and higher critical angle, so less total internal reflection occurs. Section D: Lenses (Aktiviti 13.4) Question: A convex lens has a focal length of 10 cm. An object of height 2 cm is placed 15 cm from the lens. Find: a) Image distance b) Magnification c) Image height Image height = m × object height =

Using Snell’s Law: n₁ sin i = n₂ sin r 1.33 × sin 35° = 1.00 × sin r 1.33 × 0.574 = sin r sin r = 0.763 r = sin⁻¹ (0.763) = 49.8° Section C: Total Internal Reflection (Aktiviti 13.3) Question: The critical angle for diamond is 24.4°. Calculate the refractive index of diamond.

| Angle of incidence, i (°) | Angle of refraction, r (°) | sin i | sin r | n = sin i / sin r | |---------------------------|----------------------------|-------|-------|-------------------| | 20 | 13 | 0.342 | 0.225 | 1.52 | | 30 | 19 | 0.500 | 0.326 | 1.53 | | 40 | 25 | 0.643 | 0.423 | 1.52 | | 50 | 31 | 0.766 | 0.515 | 1.49 | Diamond has a high refractive index (2

Magnification, m = v/u = 30/15 =

1/10 = 1/15 + 1/v 1/v = 1/10 – 1/15 = (3 – 2)/30 = 1/30 v = 30 cm (Image distance) Section D: Lenses (Aktiviti 13

n = 1 / sin c n = 1 / sin 24.4° n = 1 / 0.413 = 2.42