
During a thunderstorm, the thunder in the sky is produced by the_____.
. Meeting of cumulonimbus clouds in the sky.
. Lightning that separates the nimbus clouds.
. Violent upward movement of air and water particles.
Select the correct answer using the codes given below.


Important Questions on Oscillations and Waves
Consider the following statements:
. A widely used musical scale called the diatonic scale has seven scales.
. The frequency of the note Sa (Sa) is Hz and that of Ni Hz.
Which of the statements given above is/are correct?

Assertion (A): A jet aircraft moving at Mach number equal to 1 travel faster at an altitude of 15 km than while moving at Mach number equal to 1 near the sea level.
Reason (R): The velocity of sound depends on the temperature of the surrounding medium.

Consider the following statements:
1. A flute of smaller length produces waves of lower frequency
2. Sound travels in rocks in the form of longitudinal elastic waves only
Which of the statements given above is/are correct?

What does the term Dolby B or Dolby C printed on tape-recorders and other sound systems refer to?


Consider the following statements:
Statement I: The velocity of sound in air increases due to the presence of moisture in it.
Statement II: The presence of moisture in the air lowers the density of air.
Which of the above statement (s) is/are correct?


Consider the following statements:
Statement I: When a particle is executing simple harmonic motion, total energy varies with time.
Statement II: Audible waves have a frequency range of kHz to MHz.
Which of the above statement (s) is/are correct?
