By properly combining two prisms made of different materials, it is possible to (choose the incorrect option)

Options

A. have dispesion without average deviation
B. have deviation without dispersion
C. have both dispersion and average deviation
D. have neither dispersion nor average deviation

Explanation

To solve the question, we need to analyze the options provided regarding the combination of two prisms made of different materials and determine which option is incorrect.

### Step-by-Step Solution:

1. **Understanding the Prisms**:
- We have two prisms made of different materials, which means they have different refractive indices (μ1 and μ2).
- When light passes through these prisms, it can undergo deviation and dispersion.

2. **Analyzing Dispersion and Deviation**:
- **Dispersion** occurs when white light is separated into its constituent colors (spectrum) as it passes through a prism.
- **Deviation** refers to the bending of light as it passes through a prism. The amount of deviation depends on the angle of the prism and the refractive index of the material.

3. **Considering the Options**:
- **Option A**: Dispersion without average deviation.
- This is possible if the prisms are arranged in such a way that the light disperses but the average deviation cancels out. This can happen if the prisms are oriented oppositely.
- **Option B**: Deviation without dispersion.
- This can occur if only one color of light is used or if the prisms are arranged such that the light deviates but does not disperse into colors.
- **Option C**: Both dispersion and average deviation.
- This is possible when white light is used, and the prisms are arranged to allow for both effects.
- **Option D**: Neither dispersion nor average deviation.
- This is incorrect because at least one of these effects must occur when light passes through prisms of different materials.

4. **Identifying the Incorrect Option**:
- Since we have established that at least one of dispersion or deviation must occur when light passes through the prisms, **Option D** (neither dispersion nor average deviation) is the incorrect option.

### Final Answer:
The incorrect option is **D**: Neither dispersion nor average deviation.