Physics
Assertion (A) : Sound waves cannot travel through vacuum.
Reason (R) : Sound travels in the form of longitudinal waves.
- both A and R are true and R is the correct explanation of A
- both A and R are true and R is not the correct explanation of A
- assertion is false but reason is true
- assertion is true but reason is false
Answer
both A and R are true and R is the correct explanation of A
Explanation
Assertion (A) is true because sound needs a material medium (solid, liquid, or gas) to propagate and in vacuum, there are no particles to transmit the vibrations — so sound cannot travel.
Reason (R) is true because in most media (especially air), sound propagates as longitudinal waves, where particles oscillate parallel to the direction of wave propagation.
Related Questions
The properties of ultrasound that make it useful, are:
- High power and high speed
- High power and good directivity
- High frequency and high speed
- High frequency and bending around the objects
Sonar makes use of:
- Infrasonic sound
- Ultrasound
- Supersonic sound
- Light
Assertion (A) : The speed of sound is maximum in gases when compared with speed in solids.
Reason (R) : The speed of sound in a medium depends on the density of medium.
- both A and R are true and R is the correct explanation of A
- both A and R are true and R is not the correct explanation of A
- assertion is false but reason is true
- assertion is true but reason is false
Assertion (A) : Sound travels faster in humid air than in dry air.
Reason (R) : The increase of moisture in air tends to decrease the density of air.
- both A and R are true and R is the correct explanation of A
- both A and R are true and R is not the correct explanation of A
- assertion is false but reason is true
- assertion is true but reason is false