An electric bell is suspended inside a sealed glass jar. When the bell rings, a student standing nearby can hear it clearly. A vacuum pump is then turned on to remove all the air from inside the glass jar.
What will the student observe as the air is being removed?
The sound of the bell becomes gradually quieter until no sound is heard at all.
The sound of the bell becomes louder as the air pressure drops in the jar.
The sound of the bell remains at the same loudness but its pitch increases.
The sound of the bell remains at the same loudness but its pitch decreases.
295 exam-style questions on CIE IGCSE Physics Sound, covering Sound. Each one has a worked solution and a mark scheme showing where the marks go.