How many images are formed when two plane mirrors are placed parallel to each other?

Options

A. One
B. Three
C. Seven
D. Infinite

Answer

To determine how many images are formed when two plane mirrors are placed parallel to each other, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Setup**: We have two plane mirrors placed parallel to each other. This means the angle (θ) between the two mirrors is 0 degrees.

2. **Use the Formula for Image Formation**: The general formula for calculating the number of images (n) formed by two mirrors is:
- If the angle θ between the mirrors is even:
\[ n = \frac{360}{\theta} - 1 \]
- If the angle θ between the mirrors is odd:
\[ n = \frac{360}{\theta} \]

3. **Substitute the Angle**: In our case, since the mirrors are parallel, θ = 0 degrees. We can substitute this value into the formula:
\[ n = \frac{360}{0} - 1 \]

4. **Analyze the Calculation**: The expression \(\frac{360}{0}\) is undefined, which indicates that the number of images formed is infinite when the mirrors are parallel.

5. **Conclusion**: Therefore, when two plane mirrors are placed parallel to each other, they form an infinite number of images.

### Final Answer:
The number of images formed when two plane mirrors are placed parallel to each other is **infinite**.

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