Question 1
Which of the following statements best describes the law of reflection?
A. The angle of incidence is equal to the angle of refraction.
B. The angle of incidence is perpendicular to the angle of reflection.
C. The angle of incidence is equal to the angle of reflection.
D. The angle of reflection is twice the angle of incidence.
Question 2
When light travels from air into water, it bends towards the:
A. Normal
B. Incident ray
C. Reflected ray
D. Tangent to the surface
Question 3
Which of the following is NOT an application of plane-polarised light?
A. Sunglasses
B. 3D cinema glasses
C. Liquid crystal displays
D. Magnifying glasses
Question 4
According to Snell's law, if the angle of incidence increases while moving from air to glass, the angle of refraction:
A. Increases
B. Decreases
C. Remains the same
D. Becomes zero
Question 5
Which of the following materials can polarise light?
A. Transparent plastic
B. Clear water
C. Polaroid filter
D. Regular window glass
Question 6
a) Explain the laws of reflection for light waves, and provide an example of how these laws are applied in everyday life. [3]
b) A light ray strikes a mirror at an angle of incidence of 40 degrees. Calculate the angle of reflection using the laws of reflection. [2]
Question 7
a) Explain Snell's law and how it governs the behaviour of light when it passes from one medium to another. Provide an example to illustrate its application. [3]
b) A light ray passes from air into a glass medium at an angle of incidence of 30 degrees. If the refractive index of glass is 1.5, calculate the angle of refraction using Snell's law. [2]
Question 8
a) Describe what is meant by plane-polarised light and explain how it is created. Provide an example of an application of plane-polarised light. [3]
b) A beam of unpolarised light is incident on a polarising filter, and only 40% of the light intensity passes through. Calculate the angle between the polarisation direction of the filter and the initial direction of polarisation of the light. [2]
Question 9
a) Explain how the laws of reflection apply to curved mirrors, such as concave and convex mirrors. Provide a real-world example that demonstrates the behaviour of light in curved mirrors. [4]
b) A concave mirror has a focal length of 15 cm. An object is placed 30 cm away from the mirror. Calculate the position and nature of the image formed by the mirror. Use ray diagrams to illustrate your answer. [5]
c) Discuss the concept of the focal point in concave and convex mirrors and explain how it relates to the formation of images. [2]
Question 10
a) Explain the phenomenon of total internal reflection and its practical applications in optical fibres. Provide an example of an optical fibre application. [4]
b) A light ray passes from water into air at an angle of incidence of 50 degrees. Calculate the critical angle for this transition, and determine whether total internal reflection will occur for this angle. [3]
c) Discuss how the critical angle varies with different pairs of media and why it is essential for understanding total internal reflection. [2]