Which of the following is/are the applications of Sound waves?
1. It is used in the cleaning of instruments, detecting cracks in buildings, machines, ultrasound machines, and echocardiograph, SONAR.
2. In the military it is used to detect enemy aircraft.
3. In astronomy, it’s used to find the speed of moving stars and in sonography.
4. X-rays
Select the correct answer using the codes given below.
1
2, 3 and 4
2
1, 2 and 3
3
1 and 2
4
1, 2, 3 and 4