Ultrasonic waves — task. Science CBSE Homework Assignments, Class 9.

1. The sound waves having a frequency more than 20,000 Hz are called:

infrasonic waves
supersonic waves
ultrasonic waves
hypersonic waves

2. The animal which cannot hear ultrasonic waves is:

bat
cow
dog
dolphin

Login or Fast registration

Exit to the topic

Did you find an error?