Sonography Principles & Instrumentation (SPI) Ultrasound Registry Practice Test

Question: 1 / 400

A 3 dB gain in intensity indicates what change?

Halving of intensity

Doubling of intensity

A 3 dB gain in intensity represents a doubling of intensity. This is based on the logarithmic nature of the decibel (dB) scale, which is commonly used in acoustics and electronics to express ratios of power or intensity.

When we refer to a gain of 3 dB, it signifies that the intensity has increased to twice its original value. This is derived from the formula for calculating decibels in relation to intensity, which is:

\[

\text{Gain (dB)} = 10 \times \log_{10} \left( \frac{I_f}{I_i} \right)

\]

In this case, \(I_f\) is the final intensity and \(I_i\) is the initial intensity. By rearranging this formula to find the ratio when the gain is 3 dB, it can be shown that:

\[

\frac{I_f}{I_i} = 10^{3/10} \approx 2

\]

This demonstrates that a 3 dB increase in intensity results in a doubling of the initial intensity. Hence, the statement that a 3 dB gain in intensity indicates a doubling is correct and aligns well with the principles of sound

Get further explanation with Examzify DeepDiveBeta

Quadrupling of intensity

No change in intensity

Next Question

Report this question

Download Sonography Principles & Instrumentation (SPI) Ultrasound Registry Practice Test PDF Study Guide
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy