Physics Final Exam Study Guide .

Physics Final Exam Study Guide . What do we call the changes that occur in a medium whenever a sound wave passes through? Name all four of these: - correct answer These are called acoustic variables, and they include: 1. Pressure 2. Density 3. Particle Vibration 4. Temperature Which type of transducer produces the following: A. A rectangular image? B. A pointed (true) sector image? C. A curved-top sector image? A "ring"-shaped image? - correct answer A. Linear B. Phased-Array C. Convex (curved-linear) D. Annular Assuming we only have one focal zone, how many pulses are required to produce one scan line of the 2-D image? - correct answer Just one pulse produces this, but there will be many echoes in the scan line (all from the same pulse) What symbol do we use to describe the number of cycles in one pulse? - correct answer We use the letter n Define each of the following, and give its symbol: A. Period B. Frequency C. Wavelength - correct answer A. Period: This is the amount of time it takes for one cycle to occur (T) B. Frequency: This is the number of cycles which occur in each second (f). C. This is the physical length (in space) of one cycle (lambda) Give the formula used to describe frequency if we know the period: - correct answer f=1/T Give the formula used to describe wavelength if we know propagation speed and frequency: - correct answer lambda=c/f