Two parallel rays of light A and B simultane ously fall on the surface of still water in a pond. If the angle of incidence of ray A is `75^@`, what will be the angle of reflection of ray B?

Options

A. `75^@`
B. `15^@`
C. `90^@`
D. Cannot be determined

Answer

To solve the problem, we need to determine the angle of reflection of ray B when ray A has an angle of incidence of 75 degrees. Here’s the step-by-step solution:

### Step 1: Understand the Law of Reflection
The law of reflection states that the angle of incidence is equal to the angle of reflection. This means that for any ray of light striking a surface, the angle at which it reflects off the surface will be the same as the angle at which it struck the surface.

**Hint:** Remember that the angle of incidence and the angle of reflection are measured from the normal (the imaginary line perpendicular to the surface).

### Step 2: Identify the Angles
In this case, ray A has an angle of incidence of 75 degrees. Since both rays A and B are parallel, they will have the same angle with respect to the normal at the point of incidence.

**Hint:** Parallel lines maintain the same angle with respect to a transversal (in this case, the normal line).

### Step 3: Apply the Law of Reflection to Ray A
Since the angle of incidence for ray A is 75 degrees, the angle of reflection for ray A will also be 75 degrees, according to the law of reflection.

**Hint:** Use the formula: Angle of Incidence = Angle of Reflection.

### Step 4: Determine the Angle of Reflection for Ray B
Since rays A and B are parallel, and ray A has an angle of incidence of 75 degrees, ray B will also have the same angle of incidence of 75 degrees when it strikes the surface. Therefore, the angle of reflection for ray B will also be 75 degrees.

**Hint:** Since both rays are parallel, their angles with respect to the normal will be the same.

### Conclusion
Thus, the angle of reflection of ray B is 75 degrees.

**Final Answer:** The angle of reflection of ray B is 75 degrees.