Waves the electromagnetic spectrum
4 marks · NormalA student reads that all electromagnetic waves can be reflected and refracted. They want to investigate this for light.
Describe a laboratory experiment the student could perform to demonstrate the reflection and refraction of visible light, mentioning the main pieces of apparatus required.
State the apparatus the student would need.
Describe the procedure for demonstrating reflection.
Describe the procedure for demonstrating refraction.
State one observation the student could make in either part.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Ray box, mirror, glass block, protractor, paper · must show Ray box, mirror, glass block, protractor, paper
(b) Shine a ray of light onto a mirror at an angle, trace incident and reflected rays, and measure angles to show the law of reflection. · must show Shine ray at mirror, trace rays, measure angles
(c) Shine a ray of light into a glass block at an angle, trace incident, refracted and emergent rays, and observe change in direction at the boundary. · must show Shine ray into glass block at angle, trace rays, observe bending/change in direction
(d) Reflected ray is seen at equal angle to incident ray, or the refracted ray bends towards the normal. · must show Observation such as ray bends or reflected at equal angle
Must show: a: Ray box, mirror, glass block, protractor, paper, b: Correct method for reflection using mirror, c: Correct method for refraction using glass block, d: Identifies reflected or refracted ray
Common mistakes: Omitting main apparatus; Forgetting to mention measuring angles or ray tracing
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · All main apparatus listed.
B2 (b) · 1 mark · Correct method to demonstrate reflection, with mention of tracing/measuring angles.
B3 (c) · 1 mark · Correct method to demonstrate refraction, including tracing emergent/refracted rays.
B4 (d) · 1 mark · Valid observation made (e.g., ray bends, reflected at same angle, etc.).
Worked solution
a) Ray box, mirror, glass block, protractor, paper b) Shine a ray at a mirror at an angle, trace incident and reflected rays, measure angles, confirm angle of incidence equals angle of reflection. c) Shine a ray into a glass block at an angle, trace incident, refracted and emergent rays, observe the change in direction inside the block. d) The reflected ray is seen at the same angle as incident; the refracted ray bends towards the normal inside the glass.