Question

The power or loudness of sound is measured on a scale of increased by a factor of 100 (=102), the sound is called twice as loud when it increased 10,000 (=104) times it is called four times as loud. The exponent of ten is called a bel and one double is one-tenth of a bel. Zero decide is chosen as the intensity of the slowest sound which is first audible or is on the threshold of hearing whereas the intensity of loudest sound is about 170 decibel, sound intensities above a level of nearly decibels produce a feeling of pain.
A. 60
B. 120
C. 140
D. 170

Answer 1

We know that the endurance of a human ear to hear a sound of maximum frequency of 20000Hz. A human ear can hear a sound of minimum frequency 20 Hz. In between 20Hz and 20000Hz, we have the audible hearing range

Complete answer:
We are quite familiar with the term known as decibel. It is a parameter to measure the intensity of sound or the signal by comparing it with a reference level on a logarithmic scale. In general, it is the measure of loudness. It measures the relative loudness of the sound in the form of ratios.

When talking about dogs, they can hear sound frequencies up to 50000Hz and we have seen special whistles that dogs can hear but we cannot hear.

We humans can hear the sound intensity not more than 120 decibels. If suppose the sound intensity is more let’s say upto 170 db then the feeling of pain occurs in the human ear.
Even the clear and comfortable perception of sound is upto 8000Hz. Beyond 8000 Hz there is a pain and difficulty experience in hearing. For old The maximum limit of hearing for the people under 50 years of age is 12000 Hz.

Hence, the correct answer is option (B).

Note: The formula for loudness of sound is L = log10 $\dfrac{I_2}{I_1}$ .Here I1 is the intensity of sound for the reference level and I2 is the intensity of sound at the given level. It is the ratio of relative measures of intensities. The sound can be also approximated in terms of frequencies.