A student is investigating the reflection of light using a plane mirror, a ray-trace sheet, and optical pins. They draw a line $X Y$ on the sheet to represent the front surface of the mirror, and draw a normal $N P$ at the midpoint $P$ . An incident ray is drawn at an angle of $40^\circ$ to the normal, and a pin $P_1$ is placed on this ray at a distance of $cm8.5\text{ cm}$ from $P$ .

Pin Placement: (i) State the minimum recommended distance between pin $P_1$ and a second pin $P_2$ on the same ray line. (ii) Explain why keeping a large distance between the pins improves the accuracy of the drawn ray.

Precautions: State two practical precautions that the student should take when placing the pins or aligning their images to ensure reliable results.

Experimental Error: Even with careful alignment, the student notices a small systematic error where the constructed reflected ray does not perfectly match the theoretical expectation $i = r$ . Suggest a practical reason related to the construction of a typical glass mirror that explains this discrepancy.

Precautions: State two practical precautions that the student should take when placing the pins or aligning their images to ensure reliable results.

3.2.1a Reflection of light

Question 14

Markscheme

3.2.1a Reflection of light

Question 14

Markscheme

3.2.1a Reflection of light

Question 14

3.2.1a Reflection of light Questions

3.2.1a Reflection of light

Question 14

3.2.1a Reflection of light Questions