Sound — Set 2
Physics · ध्वनि · Questions 11–20 of 60
The pitch of a sound is mainly related to its?
Correct Answer: B. Frequency
Pitch depends primarily on the frequency of vibration. Higher frequency sound waves are generally perceived as higher pitch. Amplitude mainly affects loudness, not pitch.
Sound waves in air are best described as?
Correct Answer: B. Light waves only
In air, particles vibrate back and forth along the direction of wave travel. This creates compressions and rarefactions in the medium. Such waves are called longitudinal waves.
A tuning fork is often used in experiments because it produces?
Correct Answer: B. Many random frequencies together
The correct answer is 'Many random frequencies together'. A tuning fork vibrates in a stable way and gives a nearly single frequency. That makes its sound close to a pure tone with minimal overtones. This is useful for demonstrating pitch and resonance clearly.
Reverberation in a hall refers to?
Correct Answer: C. Persistence of sound due to multiple reflections
Reverberation is the lingering of sound after the source stops. It happens because sound reflects many times from walls and surfaces. Proper acoustic design controls reverberation for clear speech and music.
Which surface is generally best for absorbing sound in a room?
Correct Answer: A. Soft porous materials like curtains
Soft porous materials trap air and convert sound energy into heat. This reduces reflections and lowers echo and reverberation. That is why carpets and curtains improve room acoustics.
A stethoscope helps a doctor mainly because it?
Correct Answer: A. Works only by producing ultrasound
The correct answer is 'Works only by producing ultrasound'. A stethoscope channels faint body sounds efficiently to the ears. Its tubing helps reduce loss and outside noise compared to open air. This makes heartbeat and breath sounds easier to hear.
Ultrasonic cleaning in liquids mainly works due to?
Correct Answer: A. Cavitation produced by high-frequency waves
High-frequency sound can create tiny bubbles that form and collapse in a liquid. This cavitation dislodges dirt from surfaces and small crevices. That is why ultrasonic cleaners are used for jewelry and precision parts.
To measure sea depth using reflected sound pulses, the principle used is?
Correct Answer: D. Time delay of echoes
A sound pulse is sent and the returning echo is detected after reflection from the seabed. The travel time helps calculate distance when the speed of sound in water is known. This method is widely used in sonar systems.
Which statement correctly distinguishes sound waves in air from transverse waves?
Correct Answer: A. Sound waves in air are longitudinal
In air, sound travels as a longitudinal wave. The particles vibrate parallel to the direction of wave motion. Transverse waves have vibrations perpendicular to the direction of travel.
The speed of sound in a medium is influenced mainly by?
Correct Answer: C. Only its shape of container
The correct answer is 'Only its shape of container'. Sound speed depends on how strongly the medium resists compression and how much mass must move. Greater elasticity generally increases speed, while greater density tends to decrease it. This is why different materials have different sound speeds.