Sonic boom is a sudden
A. Loud noise by passing train
B. Sound of overflying helicopter
C. Vibrations by supersonic jet
D. Continuous sound by industrial and commercial areas

Hint: The speed sound in air is 343 m/s. The objects travelling greater than speed of sound are referred to as supersonic objects. Recall from the options which object can attain the speed of sound.

Complete answer:
Let’s first discuss the meaning of sonic boom. We have heard about the objects travelling faster than the speed of sound that is greater than 343 m/s. When an object travels greater than the speed of sound, the speed of this object is referred to as supersonic speed. When such objects break the sound barrier by travelling faster than the speed of sound, it makes a huge sound that we call sonic boom.

As we know the supersonic jets can crack the speed of sound by travelling greater than the speed of sound. When the supersonic jet travels through air greater than the speed of sound, it creates a shock wave or pressure wave in front and behind the jet. This leads to the huge emission of sound energy which can be heard from miles away. Therefore, we can say that the option C is the correct answer.

We know that the train and helicopters cannot attain the speed greater than the speed of sound. Thus, the option A and B are incorrect. As we have discussed earlier, the loud sound does not make the sonic boom but the speed of the objects greater than the speed of sound make the sonic boom. Therefore, the option D is incorrect.

So, the only correct answer is option C.

Note:Always check whether you are referring to the supersonic speed as the speed greater than the speed of sound and not the speed of light. No animate or inanimate objects can attain the speed of light. The speed of sound changes with the temperature and it is 343 m/s at room temperature.