The angle of a prism is `30^(@)`. The rays incident at `60^(@)` on one refracting face suffer a deviation of `30^(@)`. Then the angle of emergence is :

Options

A. `0^(@)`
B. `30^(@)`
C. `60^(@)`
D. `90^(@)`

Answer

To solve the problem, we need to find the angle of emergence (E) of a ray passing through a prism. The given data includes:

- Angle of the prism (A) = 30°
- Angle of incidence (i) = 60°
- Angle of deviation (D) = 30°

We can use the formula that relates these angles in a prism:

\[ A + D = i + E \]

### Step-by-Step Solution:

1. **Write down the known values:**
- Angle of prism (A) = 30°
- Angle of incidence (i) = 60°
- Angle of deviation (D) = 30°

2. **Substitute the known values into the formula:**
\[ A + D = i + E \]
Substituting the values:
\[ 30° + 30° = 60° + E \]

3. **Simplify the equation:**
\[ 60° = 60° + E \]

4. **Isolate E:**
To find E, subtract 60° from both sides:
\[ E = 60° - 60° \]
\[ E = 0° \]

5. **Conclusion:**
The angle of emergence (E) is 0°.

### Final Answer:
The angle of emergence is \( 0° \).