Question

module 7a
total internal reflection conceptual question
consider scenarios a to f in which a ray of light traveling in material 1 is incident onto the interface with material 2. (figure 1)
figure
for which of these scenarios is total internal reflection possible?
select all that apply.
view available hint(s)
a
b
c
d
e
f
submit
part b complete previous part(s)
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Explanation:

To determine total internal reflection (TIR) possibility, recall TIR conditions: 1) Light travels from a medium with higher refractive index (\(n_1\)) to lower (\(n_2\), so \(n_1 > n_2\)); 2) Incident angle \(\theta_1\) exceeds the critical angle. Without the figure, assume scenarios with \(n_1 > n_2\) and \(\theta_1\) sufficient. For example, if a scenario has \(n_1 > n_2\) (e.g., water to air) and \(\theta_1 \geq \text{critical angle}\), it qualifies. From the options, we analyze each:

• A: If \(n_1 \leq n_2\), TIR impossible.
• B: If \(n_1 > n_2\) and \(\theta_1\) meets criteria, TIR possible (hence checked).
• C–F: Depends on \(n_1, n_2\) and \(\theta_1\), but the selected B likely satisfies \(n_1 > n_2\) and \(\theta_1 \geq \text{critical angle}\).

Answer:

B (assuming B’s scenario has \(n_1 > n_2\) and \(\theta_1\) ≥ critical angle for TIR). If multiple apply, but based on the check, B is selected.