THERAPEUTIC INTERVENTIONS Practice Exam
#2 Questions with 100% Verified Answers Latest
Versions 2025 Graded A+
which way do electrons flow
negative to positive
cathodes are
negative electrodes (black)
anodes are
positive electrodes (red)
what 2 things are needed for direct flow to occur
1. complete circuit (- and +)
2. sufficient "push" to propel the electricity
what is the basic unit of charge
coulomb
what is current
rate of flow of electrons through a conductor
what is current measured in
amps
Milliamperes seconds (mAs) is
1/1000
Microamperes (uA) is
1/1,000,000
what is voltage
electrical pressure of force that causes current to flow through a
conductor
what is voltage measured in
volts
what is resistance/impedance
opposition by a conductor to the passage of current
what is resistance measured in
ohms
what is the relationship between current and voltage
they are directly proportional
,what is relationship between current and resistance
they are inversely proportional
what is the equation that involves current, voltage and
resistance
I = V/R
I = current
V = voltage
R = resistance
what are 4 factors that influence resistace
1. material of circuit
2. length of circuit
3. cross-sectional area of circuit
4. temperature
when it comes to the material of the circuit, more free
electrons means
less resistance
if the length of the circuit is shorter that means
less resistance
the greater the cross section of a circuit and the wider it is
means
less resistance
the higher the temperature of a circuit means that
less resistance
monophasic means
direct current
biphasic means
alternating current
pulsatile current
non-continuous flow of direct or alternating current
what are the 2 types of stimulators
1. constant current stimulators
2. constant voltage stimulators
what are the 3 characteristics of constant current stimulators
, 1. YOU set the current
2. not harmful for patient
3. set in milliamps
disadvantages of constant current stimulators
1. resistance increases (electrode is loose) --> voltage
automatically increases
2. skin burns due to current density
2 characteristics of constant voltage stimulators
1. set up in volts
2. current varies as resistance changes
disadvantage of constant voltage stimulators
1. decreased resistance, current intensity increases which will
increases sensation causing discomfort
common shapes of waves
- sine
- triangular
- square
what is the phase of a wave described as
the portion of the current that rises above or below the baseline
currents can have either 2 types of phases, what are they
1. monophasic (1 phase)
2. biphasic (2 phase)
what are the characteristics of a direct current
1. monophasic
2. continuous unidirectional flow of charged particles
3. positive or negative
direct currents can traditionally be called
galvanic stimulators
what is the one true device that has a true direct current
iontophoresis (turn on and stays on)
characteristics of alternating currents
1. biphasic
2. bidirectional flow of charged particles
3. symmetrical or asymmetrical
4. polarity is not an issue unless asymmetrical (zero net charge)
#2 Questions with 100% Verified Answers Latest
Versions 2025 Graded A+
which way do electrons flow
negative to positive
cathodes are
negative electrodes (black)
anodes are
positive electrodes (red)
what 2 things are needed for direct flow to occur
1. complete circuit (- and +)
2. sufficient "push" to propel the electricity
what is the basic unit of charge
coulomb
what is current
rate of flow of electrons through a conductor
what is current measured in
amps
Milliamperes seconds (mAs) is
1/1000
Microamperes (uA) is
1/1,000,000
what is voltage
electrical pressure of force that causes current to flow through a
conductor
what is voltage measured in
volts
what is resistance/impedance
opposition by a conductor to the passage of current
what is resistance measured in
ohms
what is the relationship between current and voltage
they are directly proportional
,what is relationship between current and resistance
they are inversely proportional
what is the equation that involves current, voltage and
resistance
I = V/R
I = current
V = voltage
R = resistance
what are 4 factors that influence resistace
1. material of circuit
2. length of circuit
3. cross-sectional area of circuit
4. temperature
when it comes to the material of the circuit, more free
electrons means
less resistance
if the length of the circuit is shorter that means
less resistance
the greater the cross section of a circuit and the wider it is
means
less resistance
the higher the temperature of a circuit means that
less resistance
monophasic means
direct current
biphasic means
alternating current
pulsatile current
non-continuous flow of direct or alternating current
what are the 2 types of stimulators
1. constant current stimulators
2. constant voltage stimulators
what are the 3 characteristics of constant current stimulators
, 1. YOU set the current
2. not harmful for patient
3. set in milliamps
disadvantages of constant current stimulators
1. resistance increases (electrode is loose) --> voltage
automatically increases
2. skin burns due to current density
2 characteristics of constant voltage stimulators
1. set up in volts
2. current varies as resistance changes
disadvantage of constant voltage stimulators
1. decreased resistance, current intensity increases which will
increases sensation causing discomfort
common shapes of waves
- sine
- triangular
- square
what is the phase of a wave described as
the portion of the current that rises above or below the baseline
currents can have either 2 types of phases, what are they
1. monophasic (1 phase)
2. biphasic (2 phase)
what are the characteristics of a direct current
1. monophasic
2. continuous unidirectional flow of charged particles
3. positive or negative
direct currents can traditionally be called
galvanic stimulators
what is the one true device that has a true direct current
iontophoresis (turn on and stays on)
characteristics of alternating currents
1. biphasic
2. bidirectional flow of charged particles
3. symmetrical or asymmetrical
4. polarity is not an issue unless asymmetrical (zero net charge)
