CBSE Class 9, Sound: Important Questions & Preparation Tips
Check out the preparation tips given below:
- Sound and its importance for us. Characters of a sound wave
- Mechanical wave and its property
- What type of energy sound is?
- Definitions of longitudinal and transverse waves
- Define wave front
- Sound is a mechanical wave. Justify
- Can sound wave travel in vacuum?
- Examples of electromagnetic waves
- Factors affecting the speed of sound
- Speed of sound in solid, liquid, and gas (very important)
- Audible range for humans and other animals
- Propagation of sound. Can sound propagate through vacuum?
- How does the sound produced by a vibrating object in a medium reach your ear?
- Why sound needs a medium to travel?
- What type of wave is represented by density-distance graph?
- Transverse wave cannot travel through gases or air. Why?
- Definition of wave length, frequency, time period, amplitude, and oscillation
- What is wave number?
- Relation between speed, frequency, and wave length
- Concept and formation of compressions (C) and rarefactions (R)
- What do you mean by quality of sound?
- Which wave property determines
(a) Loudness? (b) Pitch?
- A person is listening to a tone of 500 Hz sitting at a distance of 450 m from the source of the sound. What is the time interval between successive compressions from the source?
- What is intensity of sound? Intensity and loudness are same or different. Explain
- A sound wave has frequency of 2 KHz and wavelength 35 cm. How long will it take to travel 1.5 Km
- Is there any difference between reflection of sound and reflection of light?
- What is echo? Echo is related to reflection or refraction?
- Numerical based on echo.(Very important)
- An echo returned in 3 s. What is the distance of the reflecting surface from the source, given that the speed of sound is 342 m s–1?
- Reverberation and its applications
- Uses of multiple reflections of sound
- Ceilings of cinema halls and conference halls are always curved. Why?
- Frequency range of ultrasound and its uses (Important)
- Expand SONAR and mention its uses
- A ship sends out ultrasound that returns from the seabed and is detected after 3.42 s. If the speed of ultrasound through seawater is 1531 m/s, what is the distance of the seabed from the ship?
- What type of sound is emitted by prey?
- Neat and clean diagram of human ear with all audible parts.
- Functions of all the parts given below:
2. Auditory canal
3. Tympanic membrane
- Name the three bones found in the middle ear
Important Questions are as below:
Q. What happens when a wave travels through a medium?
1) Particles are transferred from one place to another
2) Energy is transferred in a periodic manner
3) Energy is transferred at a constant speed
4) None of the above statements is applicable
Q. Bats detect the obstacles in their path by receiving the reflected
1) Ultrasonic waves
2) Electro-magnetic waves
3) Radio waves
4) Infrasonic waves
Q. The physical quantity, which oscillates in most waves, is
1) Wave length
Q. The distance between a compression and the next rarefaction of a longitudinal wave is __________.
Q. When is echo heard?
1) If the time interval between original sound and reflected sound is more than 1/10 sec.
2) If the time interval between original sound and reflected sound is less than 1/20 sec.
3) If the time interval between original sound and reflected sound is less than 1/10 sec.
4) If the time interval between original sound and reflected sound 1/20 sec.
Q. What type of sound wave can propagate in solids?
1) Longitudinal only
2) Transverse only
3) Either longitudinal or transverse
4) Non mechanical wave only
If you have any Question/Point on the above information, please ask/discuss it in the CBSE Group