Final answer:
An amplifier is used to boost the voltage level of an analog signal, measured in decibels (dB). With a 40.0 dB increase in sound intensity level, the amplitude of a sound wave multiplies by a factor of 100.
Step-by-step explanation:
The device used to increase the voltage level of an analog signal at the beginning of a long cable run is known as an amplifier, and the increase in signal strength is measured in decibels (dB). This is essential in preventing signal loss over the distance of the cable. When the sound intensity level increases by 40.0 dB, the amplitude of a sound wave increases by a factor of 100. This is because sound intensity is proportional to the amplitude squared, and each 10 dB increase represents a tenfold increase in sound intensity. As such, a 40 dB increase would be a tenfold increase taken to the power of four (10⁴), which is equal to an increase by a factor of 100 in amplitude.