Question

8
two tuning forks are struck at the same time. their sound is observed to become
louder and softer at regular intervals. this is caused by wave
condensation
refraction
interference
amplification
9
the tendency of sound waves to bend when they pass from one medium to a
different medium is known as
refraction
reflection
resonance
interference
10
which phenomenon is represented by the diagram shown?
reflection
refraction
diffraction
polarization

Explanation:

• Question 8: Wave interference occurs when two waves superpose. When they are in - phase (constructive interference), the sound is louder; when out - of - phase (destructive interference), the sound is softer. Condensation is related to the compression of a medium in a sound wave (not the loud - soft variation). Refraction is the bending of waves when passing through different media. Amplification is an artificial increase in signal strength (not a natural wave phenomenon here).
• Question 9: Refraction is the bending of waves (including sound waves) when they pass from one medium to another. Reflection is the bouncing back of waves. Resonance is the phenomenon where a system vibrates at a higher amplitude at certain frequencies. Interference is the superposition of waves.
• Question 10: Reflection is the bouncing back of waves. In the diagram, the waves are bouncing off a surface (represented by the oval shape). Refraction would show a change in direction as the wave enters a new medium. Diffraction is the spreading of waves around obstacles. Polarization is a property of transverse waves related to the orientation of oscillations.

Answer:

• 8. C. interference
• 9. A. refraction
• 10. A. reflection