Sound Grade 8 ICSE

Which of these are not true about sound?

• Sound is a type of energy.

• Sound travels in longitudinal waves.

• Sound is produced by vibrations.

• Sound, once produced, travels upwards.

• Sound travels fastest in low density mediums.

The speed of sound in a medium depends on: (Mark all that apply)

• Density

• Temperature

• Elasticity

• Ambient Light

Which of these is true?

• The sun gives us light but not sound.

• The sun generates sound but it doesn't reach us because sound cannot travel in a vacuum.

• The sound that reaches the Earth from the sun is not in the hearable frequency.

In this image, the sound in the purple waves will be ____________ compared to the sound in the black wave (the first wave)

• More shrill

• Louder

• More melodious

One compression and one rarefaction make up a

• Time Period

• Wavelength

• Amplitude

• Frequency

Mark all the pairs that are correctly matched:

• Frequency - Pitch

• High temperature = High wave speed

• Amplitude = Loudness

• Tension = Loudness

Sushruta has matched the characteristics of a sound wave with their SI unit, but you know she hasn't done all of them right. Mark all the ones that she has done incorrectly.

• Frequency - Hertz

• Amplitude - A

• Wavelength - meter

• Wave Speed - m/s

• Time Period - Seconds

Surya has tried to match the symbols to the characteristics. As usual, they are not as smart as you and have got some stuff wrong. Mark everything that is wrong. 

• Wavelength -  $\gamma$  

• Wave speed - V

• Amplitude  - A

• Frequency - V

• Time Period - T

The number of oscillations completed per unit time by sound. What is this?

• Amplitude

• Frequency

• Wave length

• Time Period

Time taken for one complete oscillation in the density of the medium is called the __________ of the wave.

• Frequency

• Time Period

• Wave length