Activity 10.2:
Aim: To study the effect of amplitude on the loudness and the effect of frequency on the pitch of sound.
Apparatus: Cathode Ray Oscilloscope (C.R.O.), audio signal generator, loudspeaker and connecting wire
Instruction
1. Arrange the apparatus as shown in Figure 10.6.
2. Adjust the audio signal generator and C.R.O. until sound is produced and the waveform can be observed on the screen of the C.R.O.
3. Fix the frequency of the audio signal generator and gradually increase the output power.
4. Listen to the sound produced and observe the waveform on the screen of the C.R.O.
Record your observation.
5. Then, fix the output power of the audio signal generator and gradually increase the frequency.
6. Listen to the sound produced and observe the waveform on the screen of the C.R.O. Record your observation.
Observation
Questions
1. What are the conclusions that can be made regarding the effect of
(a) amplitude on loudness?
(b) frequency on the pitch of sound?
2. Explain the relationship between the increase in amplitude and the changes in the sound produced with reference to vibration energy.
3. If an object produces vibration at a high amplitude and frequency, what will happen to the sound produced?
Answer:
1. (a) Loudness increases when amplitude increases.
(b) Pitch of sound increases when frequency increases.
2. When amplitude increases, size of vibration of wave also increases. A louder sound is produced.
3. A louder and higher pitch of sound is produced.
Aim: To study the effect of amplitude on the loudness and the effect of frequency on the pitch of sound.
Apparatus: Cathode Ray Oscilloscope (C.R.O.), audio signal generator, loudspeaker and connecting wire
Instruction
1. Arrange the apparatus as shown in Figure 10.6.
2. Adjust the audio signal generator and C.R.O. until sound is produced and the waveform can be observed on the screen of the C.R.O.
3. Fix the frequency of the audio signal generator and gradually increase the output power.
4. Listen to the sound produced and observe the waveform on the screen of the C.R.O.
Record your observation.
5. Then, fix the output power of the audio signal generator and gradually increase the frequency.
6. Listen to the sound produced and observe the waveform on the screen of the C.R.O. Record your observation.
Observation
Questions
1. What are the conclusions that can be made regarding the effect of
(a) amplitude on loudness?
(b) frequency on the pitch of sound?
2. Explain the relationship between the increase in amplitude and the changes in the sound produced with reference to vibration energy.
3. If an object produces vibration at a high amplitude and frequency, what will happen to the sound produced?
Answer:
1. (a) Loudness increases when amplitude increases.
(b) Pitch of sound increases when frequency increases.
2. When amplitude increases, size of vibration of wave also increases. A louder sound is produced.
3. A louder and higher pitch of sound is produced.