bank spring 2024 - student.pdf

1 1. What are the two types of waves in regard to medium needs Mechanical and Electromagnetic waves 2. Ultrasound waves are classified as which type of wave? Longitudinal mechanical waves 3. Which part of a transverse wave represents the high...

1 1. What are the two types of waves in regard to medium needs Mechanical and Electromagnetic waves 2. Ultrasound waves are classified as which type of wave? Longitudinal mechanical waves 3. Which part of a transverse wave represents the highest points? Crests 4. How is frequency defined in wave terminology? The number of waves produced in a unit time 5. What is the range of frequency of ultrasound?a. below 20 Hz above 20 kHz 6. What does the reverse Piezoelectric Effect refers to? Electrical energy converting to Mechanical energy 7. What are the main components of an LC oscillator? Inductive coil and capacitor 8. How is energy storage different between a capacitor and inductive coil in an LC oscillator? Capacitor stores energy in electric field and inductive coil stores energy in magnetic field 9. What determines the amount of damping in an LC circuit?. Quality or Q-factor of the circuit 10. What is the condition of resonance in a LC tank circuit? Capacitive and inductive reactance must be equal 10b. In a practical LC circuit, what happens to the amplitude of the oscillatory voltage? It decreases at each half cycle 2 11. What is affect the change in length of a ferromagnetic rod in the magnetostriction ultrasonic generator? Strength of the magnetic field 12. How is resonance achieved in a magnetostriction ultrasonic generator?. Matching the frequency of the vibrating rod with the circuit frequency 13. Which of the following is an advantage of a magnetostriction ultrasonic generator? It is easily available and inexpensive 14. What type of signal does a piezoelectric crystal produce while receiving ultrasound?. Alternating potential difference 15. Why does using a quartz crystal make a piezo-electric oscillator more efficient?. It increases stability in frequency 3 16. What is the general range for therapeutic ultrasound intensity levels? 0.1-3.0 W/cm2 17. What is happened to the energy delivered to the patient when the ultrasound amplitude is doubled? energy is quadrupled 18. What is the Doppler effect primarily related to in sound waves? Frequency and pitch 19. What is the significance of increasing in the relative intensity by 3dB? It corresponds to a doubling of the absolute intensity 20. Which zone is characterized by a regular sonic field due to insignificant path length differences? Fraunhofer zone 21. What is the unit of power for ultrasound beams?. Joule/second 22. How is therapeutic shock waves distinct from ultrasound in terms of wave behavior?. Shock waves are more intense and faster 23. How does the frequency of ultrasound waves relate to their depth of penetration in tissues?. Lower frequency = deeper penetration 24. What is the primary purpose of using pulsed ultrasound?. Prevent excessive tissue heating 25. What is the advantage of ultrasound applicator with lower Beam Non- Uniformity Ratio (BNR)?. Wave uniformity increases 4 26. which of the following is a Property of electric charge? Electric charge is quantized 27. What is Coulomb's law in electricity? The force between two charge is directly proportional to the product of the charges, q1 , q2, and inversely proportional to the square of the separation r between the charges 28. What is the electric field at a point?. The amount of electric force acting on a positive test charge at that point 29. What is Electric Flux?. The measure of electric field lines penetrating normally on unit area of this surface. 30. For resistance and resistivity of a material, which of the following relationship is true? Resistance is directly proportional to resistivity 5 31. What is the unit of potential difference in a circuit? Volt 32. What is the frequency of a wave with a periodic time of 0.02 seconds? 50 Hz 33. When comparing different waves, what does the Peak-to-peak value measure? Difference between lowest negative amplitudes and highest positive amplitude on both sides 34. What is the Root-Mean-Square (RMS) value used for in AC circuits? a. Measures the distance between two peaks b. Compares one wave to another in terms of maximum values c. Relates the amount of AC to DC values for heating effect d. Determines the average value over one cycle 35. According to Ohm's Law, what is the relationship between voltage (V), current (I), and resistance (R)? V=IxR 36. What is the value of voltage at resistance R1? 1V 37. What is the value of voltage at resistance R1? 3V 38. Which of the following units represents electric current? Ampere 39. if R1 =2 ohm and R2 = 4 ohm are connected in parallel, then what is the value of the total resultant resistance R of them? 1.33 ohm 40. If R1 =2 ohm and R2 = 4 ohm are connected in series , then what is the value of the total resultant resistance R of them? 6 ohm  6 41. What is the unit of capacitance for a capacitor? Farads 42. What force limits the addition of more charge on the plates of a capacitor? Coulombic repulsion 43. In charging process of the capacitor, when the initial amount of charge on a capacitor is small, how does the voltage across the capacitor change? Increases rapidly 44. In charging process of the capacitor, when more charge is stored on the plates of the capacitor, how does the voltage across the capacitor change? Increases more slowly 45. Which statement is false about a dielectric material in a capacitor? It decreases the capacitance of the capacitor 46. Which equation represents the charge stored on the plates of a capacitor? Q = CV 47. Which of the following actions increases the capacitance of a capacitor? Increasing surface area of plates 48. What is happened to the total capacitance when capacitors are connected in series? Decreases 49. What is the total capacitance CT of two capacitors C1 and C2 connected in series? CT = 1 / (1/C1 + 1/C2) 50. What is the total capacitance CT of two capacitors C1 and C2 connected in parallel? CT = C1 + C2 51. What is happened to the total capacitance when capacitors are connected in parallel?. Increases 7 52. What is the characteristic of Direct Current (DC)? Continuous unidirectional flow of charged particles 53. How is Alternating Current (AC) defined? Intermittent (variable) bidirectional flow of charged particles 53. What is the frequency range of Low Frequency Currents? 1-1000 Hz 54. What is the frequency range of high Frequency Currents? 1000,000 Hz or greater 55. What effect do High Frequency Currents have on sensory and motor nerves? No effect on nerves 56. What is the defining feature of Monophasic current? Has only one phase on the same side of baseline 57. How are Biphasic currents characterized? Two phases on opposite sides of baseline 59. What does Pulse Frequency measure? Number of pulses in a unit time 58. What is Pulse Duration also known as? Pulse Width 60. Define Phase Duration in electrical pulses. Time for one phase to complete its rout 61. What does Interpulse Interval refer to? Time between pulses 62. What is Burst modulation in electrical currents? A series of groups of pulses delivered at a specified frequency over a specified time interval followed by a brief time interval without charged particle movement. 63. What is the Duty Cycle if the on time is 20 seconds and off time is 30 seconds? 40% 64. What is the purpose of Beat Modulation in electrical currents? Create interference pattern 65. Which of the following is not related to Faradic currents? It can stimulate denervated muscles 67. Which of the following is not related to galvanic current? Its frequencies more than 50Hz 8 68. What is meant by the ability of a material to absorb energy up to the proportional limit? Resilience 69. What is considered as a measure of the material resistance to the plastic deformation? Yield Strength 70. What is meant by the ability of a material to absorb energy up to the fracture? Toughness 71. What is represent the whole area under the stress-strain curve of a material? Toughness 72. Fatigue occurs when a material is subjected to.................. load Dynamic 73. What is meant by the ability of a material to undergo permanent compressive deformation without fracture? Malleability 74. What is meant the ability of a material to undergo permanent tensile deformation without fracture?. Ductility 75. In which type of material the Yield strength and breaking strength are nearly the same? Brittle materials 76. Elastic modulus represents the....................... of materials Rigidity 9 77. What is the main difference between statics and dynamics in mechanics? Statics involves objects at rest or moving without acceleration while dynamics involves objects in motion with acceleration 78. What is the primary concern of kinetics? Analysis of forces causing motion  79. What is the primary concern of Kinematics? Description of the motion 80. Which type of lever has the resistance placed between the fulcrum and the force? Second class 81. Which type of lever has the fulcrum placed between the resistance and the force? First class 82. Which type of lever has the force placed between the fulcrum and the resistance?. Third class 83. How does the location of a lever's axis improve its mechanical advantage? Closer axis to resistance increases mechanical advantage 84. What does the term "mechanical advantage" refer to in biomechanics? It represents the force reduction needed to move a resistance Acoustic impedance Coulomb's law Direct current (dc): the capacitor potential difference The piezoelectric effect. Lc oscillator Doppler effect Yield strength