post test physics part 2

Continuous wave Doppler is a modality of ultrasound that is best used for:

• Generating high-resolution images

• Measuring velocities of objects in motion

• Measuring distances of far-away objects

• Resolving issues with range ambiguity

Which of the following malfunctions causes the line isolation monitor to alarm?

• Total electrical current exceeding circuit capacity

• Interruption of current to electrical outlets caused by a circuit breaker

• Surge of current in the main power supply

• Flow of current to ground in the isolated circuit

Kinetic energy is a property only of the:

• pressure

• temperature

• volume

• density

The pressure and volume per minute delivered from the central hospital oxygen supply are

• 2100 psi and 650 L/min

• 75 psi and 100 L/min

• 50 psi and 50 L/min

• 1600 psi and 100 L/min

Appropriate definition: relationships between pressure, volume and area

• pressure = volume/area

• force =

  pressure x area

• area = pressure/force

• pressure = area/force

During normal laminar airflow, resistance is dependent on which characteristic of oxygen?

• Temperature

• Density

• Viscosity

• Molecular weight

The reason a patient is not burned by the return of energy from the patient to the ESU (electrosurgical unit, Bovie) is that

• The exit current density is much less than that at the hand piece

• The coagulation side of this circuit is positive relative to the ground side

• Resistance in the patient ’s body attenuates the energy

• The exit current density is much less than 3 MHz

Regarding Diathermy safety

• Bipolar diathermy requires a passive electrode (‘diathermy plate’)

• Ohm’s law states that current = voltage x resistance

• Diathermy works because there is a high current density at the active electrode

• The heat energy produced by cautery is proportional to the current at the tip of the active electrode

Concerning humidity and humidification of gases

• Relative humidity is the ratio of absolute humidity to saturated humidity at a specified temperature

• Heat and moisture exchangers can't achieve 50% humidity

• Operating theatre humidity should be maintained at no more than 30%

The pin-index safety system is designed to prevent the incorrect connection of what to the anesthesia machine?

• Scavenger unit

• Flow meter

• Gas cylinder

• Pipeline supply