Which of the following is used to detect cracks and flaws in metal blocks?

Correct option is B

The correct answer is (b) Ultrasound.
· Ultrasound waves are sound waves with frequencies higher than the upper audible limit of human hearing.
· They are used in various industrial applications, including detecting cracks and flaws in metal blocks.
· This technique, known as ultrasonic testing, involves sending high-frequency sound waves into the material and analyzing the reflected waves to detect any discontinuities.
· It is a non-destructive testing method, meaning it does not damage the material being tested.
Information Booster:
· Reverberation: The persistence of sound in an enclosed space due to multiple reflections after the sound source has stopped.
· Echo:The reflection of sound that arrives at the listener some time after the direct sound.
· Sound Navigation and Ranging (SONAR): A technique that uses sound propagation to navigate, communicate, or detect objects under the surface of the water.