An EM wave is normally incident on a boundary between two materials ($n_1 \ll n_2$). If the incident wave starts in **material 2**, 1. most of the wave is reflected back; very little of the wave transmits through material 1 2. some of the wave is reflected back; some of the wave transmits through material 1 3. very little of the wave is reflected back; most of the wave transmits through material 1 4. ??? Note: * Correct Answer: A

An EM wave is normally incident on a boundary between two materials ($n_1$ is close to $n_2$). If the incident wave starts in **material 1**, 1. most of the wave is reflected back; very little of the wave transmits through material 1 2. some of the wave is reflected back; some of the wave transmits through material 1 3. very little of the wave is reflected back; most of the wave transmits through material 1 4. ??? Note: * Correct Answer: C

## Annoucements * Quiz 5 (next Friday) * Construct the expression for plane wave given a description * Both complex and real expressions * Combine two plane waves and describe the resulting superposed wave

**Claim:** For a wave heading towards a boundary between two media at an oblique angle, $\omega_I = \omega_R = \omega_T$. 1. True 2. False Note: * Correct Answer: A * All are the same

**Claim:** For a wave heading towards a boundary between two media at an oblique angle, at the boundary, $\mathbf{k}_I\cdot\mathbf{r} = \mathbf{k}_R\cdot\mathbf{r} \neq \mathbf{k}_T\cdot\mathbf{r}$. 1. True 2. False Note: * Correct Answer: B * All are equal