The whistling sound from the hearing aids represents that your hearing aids is working perfectly ad is known as the "feedback". So, the given statement is true.
Answer: Option A
<u>Explanation:</u>
It's often sounds irritating when a hearing aids of your grandpa or Grandma whistles. especially, when they put them out of their ears. Actually, this feedback sound from hearing aids occur when the sounds from the outer side bounces back to the microphone of the hearing aids.
The sound bounces back when it doesn't gets inside of your ear canal so that one can hear the sound through the hearing aid. When the sounds bounces back in the hearing aid, it get re-amplified and thus we hear the whistle sound which is known as the feedback of the device.
It's not always the feedback sound though. Sometimes the device whistles when it has some mechanical defect or when one hugs the other one or water gets inside and damaged the whole system.
Last One.... If Im not Wrong!
Burning of Fossil Fuels, Increase the CO2 And therefore the Green Effect!!
To solve this problem it is necessary to apply the concepts related to the Moment. The moment in terms of the Force and the time can be expressed as

F = Force

At the same time the moment can be expressed in terms of mass and velocity, mathematically it can be given as

Where
m = Mass
Change in velocity
Our values are given as

By equating the two equations we can find the Force,



Therefore, the net average force will be:

The negative symbol indicates that the direction of the force is upwards.
The answer is A. the same.
Since the container is sealed, their will be no loss of material from the container which means that the mass won’t vary.