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Question 1. Which physical law states that the intensity of an electromagnetic wave decreases proportionally to the square of the distance from its source? A) Ohm’s Law B) Inverse Square Law C) Snell’s Law D) Fourier’s Law Answer: B Explanation: The Inverse Square Law describes how intensity diminishes with the square of the distance from a point source. Question 2. In tissue interaction, which phenomenon occurs when an acoustic wave changes direction as it passes from one medium to another with a different acoustic impedance? A) Absorption B) Reflection C refraction D) Transmission Answer: C Explanation: Refraction is the bending of a wave when it enters a medium with different impedance. Question 3. During the proliferative phase of wound healing, which cellular activity is predominant? A) Neutrophil infiltration B) Fibroblast collagen synthesis
C) Platelet aggregation D) Epidermal desquamation Answer: B Explanation: Fibroblasts proliferate and produce collagen to rebuild the extracellular matrix. Question 4. According to the Gate Control Theory, pain can be inhibited by stimulating which type of nerve fibers? A) C fibers B) A-δ fibers C) A-β fibers D) D fibers Answer: C Explanation: Activation of large-diameter A-β fibers closes the “gate” in the dorsal horn, reducing pain transmission. Question 5. Cryotherapy reduces metabolic rate in tissues by approximately what percentage per 1 °C drop in temperature? A) 2% B) 5% C) 8% D) 10% Answer: D Explanation: Metabolic activity decreases about 10% for each degree Celsius reduction in tissue temperature.
D) Light absorption Answer: B Explanation: Short-wave diathermy converts high-frequency electromagnetic energy into deep tissue heat. Question 9. Which safety precaution is essential before applying therapeutic heat to a patient with decreased sensation? A) Increase temperature by 2 °C above normal B) Perform a pin-prick sensation test C) Apply heat for >30 minutes continuously D) Use the highest intensity setting Answer: B Explanation: Sensation testing ensures the patient can perceive excessive heat and prevents burns. Question 10. In TENS therapy, a high-frequency (80– 120 Hz) and low-pulse duration setting is primarily used for: A) Muscle strengthening B) Sensory-level analgesia C) Motor re-education D) Deep tissue heating Answer: B Explanation: High-frequency, low-duration TENS stimulates sensory fibers to achieve analgesia without muscle contraction.
Question 11. Which waveform is characteristic of Russian current? A) Continuous sinusoidal wave B) Burst-modulated 2.5 kHz carrier with 50 Hz bursts C) Asymmetric biphasic rectangular pulses D) Pulsed square wave at 1 MHz Answer: B Explanation: Russian current uses a 2.5 kHz carrier delivered in 50 Hz bursts with a 50% duty cycle. Question 12. For interferential current (IFC), the “beat frequency” is generated by: A) Two identical frequencies interfering constructively B) Two high-frequency carrier waves differing by a low frequency C) A single low-frequency wave modulated by amplitude D) Alternating polarity of a single waveform Answer: B Explanation: IFC combines two high-frequency carriers (e.g., 4000 Hz and 4100 Hz) to produce a low-frequency beat (100 Hz) that penetrates deeper. Question 13. Which parameter most directly influences the depth of penetration of therapeutic ultrasound? A) Pulse duration B) Frequency C) Duty cycle D) Treatment time
B) Creating micro-cavitation that disrupts the stratum corneum C) Electrophoretic migration of ions D) Mechanical stretching of collagen fibers Answer: B Explanation: Ultrasound-induced cavitation increases skin permeability, facilitating drug passage. Question 17. Which of the following medications is typically delivered via iontophoresis using a cathodal (negative) electrode? A) Lidocaine (base) B) Dexamethasone sodium phosphate (anion) C) Hydrocortisone (neutral) D) Ketorolac (cation) Answer: B Explanation: Anionic dexamethasone is repelled by the negative electrode, driving it into tissue. Question 18. High-Voltage Pulsed Current (HVPC) is most commonly employed for: A) Deep tissue heating B) Wound debridement C) Edema reduction and wound healing D) Muscle hypertrophy Answer: C
Explanation: HVPC promotes fibroblast activity, reduces edema, and accelerates wound repair. Question 19. Functional Electrical Stimulation (FES) differs from NMES primarily because: A) FES uses higher frequencies (>100 Hz) B) FES is synchronized with functional tasks such as gait C) FES delivers continuous current without off-cycles D) FES only stimulates sensory fibers Answer: B Explanation: FES is applied during purposeful movements to assist or retrain functional activity. Question 20. In diathermy, the capacitive method concentrates energy primarily in: A) Bone tissue B) Muscle tissue C) Subcutaneous fat D) Joint capsule Answer: C Explanation: Capacitive electrodes create an electric field that preferentially heats tissues with higher resistance, such as fat. Question 21. Which type of diathermy uses magnetic fields to induce currents in deep tissues? A) Capacitive short-wave diathermy B) Inductive short-wave diathermy
Question 24. In spinal traction, a “static” traction technique differs from “intermittent” traction by: A) Applying a continuously varying force B) Maintaining a constant force throughout the session C) Using higher frequencies of force pulses D) Combining flexion and extension movements Answer: B Explanation: Static traction holds a steady force, whereas intermittent traction alternates force on/off cycles. Question 25. The primary therapeutic goal of cervical traction in a patient with a herniated disc is to: A) Strengthen cervical musculature B) Reduce intradiscal pressure and promote disc re-traction C) Increase blood flow to the posterior neck muscles D) Mobilize facet joints Answer: B Explanation: Traction decompresses the disc, lowering pressure and facilitating disc material reposition. Question 26. Intermittent pneumatic compression (IPC) devices are most effective for preventing: A) Muscle atrophy B) Deep vein thrombosis (DVT) C) Tendon adhesions
D) Bone demineralization Answer: B Explanation: IPC promotes venous return, reducing stasis and the risk of DVT. Question 27. Which compression modality provides the highest level of graduated pressure for lymphedema management? A) Short-stretch bandaging B) Long-stretch bandaging C) Sequential pneumatic compression D) Elastic sleeve Answer: C Explanation: Sequential pneumatic devices deliver graded, cyclic pressures that effectively mobilize lymph. Question 28. The buoyant force exerted by water on a submerged body is described by: A) Archimedes’ principle B) Bernoulli’s principle C) Pascal’s law D) Newton’s third law Answer: A Explanation: Archimedes’ principle states that the upward buoyant force equals the weight of the displaced fluid.
Answer: C Explanation: Recording exact parameters ensures reproducibility, safety, and compliance with standards. Question 32. Evidence-based practice suggests that for most musculoskeletal conditions, active exercise is: A) Less effective than passive modalities alone B) Equally effective as high-intensity laser therapy C) More effective than any single passive modality D) Ineffective without concurrent ultrasound Answer: C Explanation: Systematic reviews show active therapeutic exercise yields superior outcomes compared with passive modalities alone. Question 33. The purpose of a Ground Fault Circuit Interrupter (GFCI) in electrotherapy equipment is to: A) Increase the intensity of the current delivered B) Prevent electrical shock by detecting leakage currents C) Measure tissue impedance automatically D) Calibrate the frequency output Answer: B Explanation: GFCIs monitor for stray currents and disconnect power to protect users from shock. Question 34. In ultrasound calibration, the “spatial peak temporal average intensity” (ISPTA) is used to assess:
A) The highest instantaneous intensity at a point B) The average intensity over the treatment area and time C) The frequency stability of the transducer D) The temperature rise in the coupling gel Answer: B Explanation: ISPTA represents the average intensity delivered across the beam over the treatment period. Question 35. Which of the following best describes the “thermal index” (TI) displayed on a therapeutic ultrasound unit? A) Ratio of delivered intensity to tissue absorption coefficient B) Estimate of the potential for tissue heating relative to a reference value C) Measurement of mechanical index for cavitation risk D) Indicator of beam focus depth Answer: B Explanation: TI predicts the likelihood of temperature rise; higher values indicate greater heating potential. Question 36. In the context of acoustic radiation, the “mechanical index” (MI) is primarily used to: A) Predict thermal effects B) Predict the likelihood of cavitation C) Determine the depth of penetration D) Measure acoustic impedance Answer: B
C) It is the difference between the two carrier frequencies and produces the therapeutic low-frequency effect D) It is unrelated to patient comfort Answer: C Explanation: The beat frequency equals the difference between the carriers, creating a low-frequency therapeutic stimulus. Question 40. In a patient receiving NMES for quadriceps strengthening, the optimal pulse duration to achieve a strong muscle contraction is: A) 10 μs B) 50 μs C) 300 μs D) 1000 μs Answer: C Explanation: Pulse durations of 200–400 μs are effective for recruiting motor units without excessive discomfort. Question 41. Which of the following best explains why 1 MHz ultrasound is preferred for treating deep muscle injuries? A) Higher absorption coefficient in bone B) Greater penetration depth due to lower attenuation C) Produces more cavitation at superficial levels D) Generates higher surface temperature Answer: B Explanation: Lower frequency waves attenuate less, allowing deeper tissue heating.
Question 42. The primary physiological effect of infrared radiant heat applied to the skin is: A) Immediate muscle contraction B) Increased collagen synthesis via photochemical reaction C) Vasodilation and increased blood flow D) Direct nerve fiber ablation Answer: C Explanation: Infrared heat causes vasodilation, enhancing circulation and metabolic activity. Question 43. Which of the following is a relative contraindication (requires physician clearance) for applying short-wave diathermy? A) Open wound B) Recent fracture within 2 weeks C) Controlled hypertension D) Mild eczema Answer: B Explanation: Recent bone healing may be disrupted by deep heating; clearance is needed. Question 44. During hydrotherapy, the term “viscosity” primarily influences: A) The buoyant force on the patient B) The resistance felt during active movements in the water C) The temperature of the water
Question 47. The most appropriate waveform for delivering iontophoresis of a positively charged drug is: A) Direct current (DC) with anode over the treatment area B) Alternating current (AC) at 1 kHz C) Pulsed biphasic current at 100 Hz D) High-voltage pulsed current (HVPC) Answer: A Explanation: DC drives positively charged ions away from the anode toward the tissue. Question 48. In the context of electrical safety, “ground fault” refers to: A) A short circuit between the two active leads B) Current flowing through an unintended path to ground, potentially through the patient C) Overheating of the electrode pads D) Failure of the device’s battery Answer: B Explanation: Ground fault occurs when current leaks to ground, posing an electrical shock risk. Question 49. Which parameter is most important to adjust when the goal is to increase muscle fatigue resistance using Russian current? A) Carrier frequency B) Burst duration C) Duty cycle D) Total treatment time
Answer: B Explanation: Extending burst duration (e.g., 10 seconds on, 10 seconds off) enhances endurance adaptations. Question 50. A patient with a recent myocardial infarction should receive which of the following modalities with caution or avoidance? A] Low-level laser therapy B] Cryotherapy C] Interferential current D] Ultrasound Answer: C Explanation: Electrical stimulation can provoke arrhythmias in post-MI patients; IFC is contraindicated. Question 51. The term “bio-stimulation” in low-level laser therapy refers to: A) Direct heating of tissues above 45 °C B) Activation of cellular processes such as ATP production without a temperature rise C) Mechanical disruption of cell membranes D) Electrical depolarization of nerves Answer: B Explanation: LLLT triggers photochemical reactions that enhance cellular metabolism without significant heat.
