Question 52 of 949
One end of a long wire is fixed while a vibrator is attached to the other end. When the vibrator is energized, the types of waves generated in the wire are
- A. stationary and longitudinal
- B. stationary and transverse
- C. progressive and transverse
- D. progressive and longitudinal
Correct Answer:
B
Explanation
The correct option for the types of waves generated in the wire when one end is fixed and a vibrator is attached to the other end is **B. stationary and transverse**.
### Detailed Explanation:
1. **Understanding Wave Types**:
- **Transverse Waves**: In transverse waves, the oscillation of particles is perpendicular to the direction of wave propagation. A common example is waves on a string, where the string moves up and down while the wave travels horizontally.
- **Longitudinal Waves**: In longitudinal waves, the oscillation of particles is parallel to the direction of wave propagation. Sound waves in air are a classic example, where air molecules compress and rarefy in the direction the wave travels.
2. **Stationary (Standing) Waves**:
- Stationary waves, also known as standing waves, occur when two waves of the same frequency and amplitude travel in opposite directions and interfere with each other. This results in certain points (nodes) where there is no movement and other points (antinodes) where the movement is maximum.
- In the case of a wire fixed at one end, when the vibrator creates waves, these waves reflect off the fixed end. The reflected waves interfere with the incoming waves, creating a pattern of nodes and antinodes, which is characteristic of stationary waves.
3. **Why Option B is Correct**:
- When the vibrator is energized, it causes the free end of the wire to oscillate, generating transverse waves. As these waves travel down the wire, they reflect off the fixed end, leading to the formation of stationary waves. The fixed end of the wire acts as a boundary condition that supports the formation of these standing waves.
- Therefore, the waves generated in the wire are both stationary (due to reflection and interference) and transverse (due to the nature of the oscillation).
### Why Other Options are Incorrect:
- **Option A: Stationary and Longitudinal**:
- This option suggests that the waves are stationary and longitudinal. However, since the wire vibrates in a direction perpendicular to the length of the wire, the waves generated are transverse, not longitudinal. Thus, this option is incorrect.
- **Option C: Progressive and Transverse**:
- Progressive waves are waves that move through a medium without reflecting back. In this scenario, while transverse waves are indeed generated, they do not remain progressive due to the fixed end of the wire causing reflection and interference. Therefore, this option is also incorrect.
- **Option D: Progressive and Longitudinal**:
- This option incorrectly states that the waves are longitudinal. As previously explained, the nature of the wave generated in the wire is transverse, not longitudinal. Additionally, the presence of a fixed end leads to the formation of stationary waves rather than progressive waves. Hence, this option is incorrect.
### Summary of Key Points:
- The waves generated in the wire are **stationary** due to reflection and interference at the fixed end.
- The waves are **transverse** because the oscillation of the wire is perpendicular to the direction of wave propagation.
- The fixed end of the wire creates nodes and antinodes, characteristic of stationary waves.
- Understanding the distinction between transverse and longitudinal waves is crucial for identifying wave types in different scenarios.
This thorough understanding of wave behavior in fixed systems will aid in your preparation for physics exams and enhance your grasp of wave mechanics.