Select the incorrect statement about cathode rays.

Options

A. Deflected by electric and magnetic field
B. Stream of electron
C. Move with same speed as that of light
D. Travel in parabolic path

Answer

To solve the question about cathode rays and identify the incorrect statement, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Cathode Rays**:
- Cathode rays are streams of electrons emitted from the cathode in a vacuum tube. They travel from the cathode to the anode.

**Hint**: Remember that cathode rays consist of electrons, which are negatively charged particles.

2. **Properties of Cathode Rays**:
- **Deflection by Electric and Magnetic Fields**: Cathode rays are deflected by electric and magnetic fields due to the charge of the electrons. This is a true statement.
- **Travel in Straight Lines**: In the absence of electric or magnetic fields, cathode rays travel in straight lines. This is also a true statement.
- **Speed of Light**: While cathode rays travel at high speeds, they do not travel at the speed of light. This statement can be misleading, but it is generally accepted that they travel at a significant fraction of the speed of light.

**Hint**: Focus on how the presence of external fields affects the path of cathode rays.

3. **Identify the Incorrect Statement**:
- The question asks for the incorrect statement. Among the properties discussed, the statement that cathode rays travel in a parabolic path is incorrect. Cathode rays do not travel in a parabolic path; they travel in straight lines unless acted upon by an external force.

**Hint**: Compare the behavior of cathode rays with that of other types of rays to clarify their path.

4. **Conclusion**:
- The incorrect statement about cathode rays is that they "travel in a parabolic path." Therefore, this is the option we need to select.

### Final Answer:
The incorrect statement about cathode rays is: **They travel in a parabolic path.**