Question
Physics Question on sound
A balloon is filled with hydrogen. For sound waves, this balloon behaves like
A
a converging lens
B
a diverging lens
C
a concave mirror
D
None of the above
Answer
a diverging lens
Explanation
Solution
As density of hydrogen is less than density of air, velocity of sound in hydrogen is greater than velocity of sound in air. Therefore, hydrogen acts as a rarer medium and the balloon behaves as a diverging lens.