How are bats able to fly in the dark?

Q. Can we hear (a) infrasonic waves (b) ultrasonic waves ?

Q.

To detect the obstacles in their path, bats produce :

(a) infrasonic waves (b) ultrasonic waves

(c) electromagnetic waves (d) radio waves.

Q. An animal that can hear ultrasonic sound waves :-

Q. Bats can produce and hear infrasonic sound.

Q. (a) What are infrasonic waves ? Name two animals which produce infrasonic waves.
(b) What are ultrasonic waves ? Name two animals which can produce ultrasonic waves.
(c) The audible range of frequencies of an average human ear is from 20 Hz to 20 kHz. Calculate the corresponding wavelengths. (Speed of sound in air is 344 ms^–1)