Waves, Information & a Speaker System — Drills · Grade 8 Science
Chapter: Waves, Sound & LightWhat these drills covers
By the end of Waves, Information & a Speaker System you should be able to:
- I can trace the linked electrical, magnetic, mechanical and sound mechanisms in a speaker.
- I can decode a supplied threshold signal and explain noise limits and different vacuum-transfer cases.
4 questions, written answer, each with a worked explanation.
Vocabulary used: signal, membrane, analog, digital, threshold, model, evidence, system boundary, assumption.
Problem 1
Answer and explanation
The time-varying input and resulting changing force are also needed to produce the membrane’s varying motion and air disturbance.
The time-varying input and resulting changing force are also needed to produce the membrane’s varying motion and air disturbance.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 2
Answer and explanation
The encoding rules, timing and how to distinguish message boundaries and symbols; the physical carrier alone does not define the meaning.
The encoding rules, timing and how to distinguish message boundaries and symbols; the physical carrier alone does not define the meaning.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 3
Answer and explanation
No. Noise can cause incorrect symbol decisions, especially near a threshold. Reliability depends on the system and code, not merely the digital label.
No. Noise can cause incorrect symbol decisions, especially near a threshold. Reliability depends on the system and code, not merely the digital label.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.
Problem 4
Answer and explanation
Sound requires material interactions in a medium. Magnetic interactions can occur across a vacuum; the two effects do not share the same air requirement.
Sound requires material interactions in a medium. Magnetic interactions can occur across a vacuum; the two effects do not share the same air requirement.
Response criteria
- Use the supplied conditions and relevant evidence.
- Explain the scientific mechanism or calculation.
- State a meaningful limitation or testable next step.