Module 10 Flashcards
Electricity is defined as that which results from_____
Mobile charges
Positive charges are ________ to negative charges, and _______ by other positive charges
Attracted
Repelled
Force of attraction or repulsion between two charges is the _______ or _________ force
Electrostatic
Coulombic 
Unit of electrical charge
(C) Coulomb:
This law states that the total amount of electrical charge in the universe is constant
Law of conservation of electric charge
E=I X R
What law does this equation represent?
Ohms law
E= Electromotive force in volts
I= Current in amperes
R= Resistance in ohms
Ohms law Formed the basis of what physiologic equation?
BP= COx SVR
SI unit of electric current (flow of charge particles)
Ampere (A)
Unit that measures the size of electrical potential
(V) Volt
E=IxR
What does each factor in this equation represent
E= electromotive force in volts (V) I= current in amperes (A) R= resistance in ohms
Si unit for Electrical energy expended doing work
Joules (J)
Electrical power equation
P= Ex I
P= electrical power in watts (w) E= voltage I= current
The equivalent of watt/seconds: used in defibrillator
Joules
SI unit for electrical power
Watts (W)
The amount of electrical work done is measured in….
Watts multiplied by unit of time (Ex. kilowatt-hour, watt-seconds or Joules)
Unit of measurement used by electrical utility companies to measure large quantities of electrical energy
Kilowatt hour
 The type of current where electrons always flow in the same direction
DC (direct current)
The type of current where electron flow reverses at regular intervals
AC (alternating current)
The sum of forces that oppose movement in AC circuit
Impedance (Z)
Opposes or has high impedance to the flow of electrons
Insulator
Permits or has low impedance to the flow of electrons
Conductor
The measure of a substances ability to store charge
Capacitance
Any two parallel conductors separated by an insulator and has ability to store charges
Capacitor
Generation of electromagnetic force in the circuit
Inductance
The net affect of inductance is to______ impedance
Increase
__________ and __________ dependent on the AC frequency.
Capacitance
Inductance
Ohms law is only accurate when applied to _____ circuits
DC
AC and DC current can be _____ or ______
Pulsed
Continuous
In DC current ohm measures resistance, while in AC current _____ measures resistance
Impedance
Defined as the sum of forces that oppose electron movement in the AC circuit including resistance capacitance and inductance
Impedance (Z)
The three factors that make up impedance
Resistance
Capacitance
Inductance
Both capacitance and inductance are influenced by the ______
Frequency (Hz, cycles per second)
Increased AC frequency causes _______ impedance

Lower
ESU has high frequency currents (0.5 to 2 million Hz) causes marked ______ in impedance
Decrease
It takes ______ as much DC current than AC current to cause V. Fib. 
X3
Electrical accidents or shocks occur when a person ________ an electrical circuit 
Completes
In the United States utility companies supply electrical energy and the form of _____ current of _____ Volts and a frequency of _____ Hz.
AC
120
60
This term refers to the number of times in one second that AC current reverses its direction of flow
Hz
What pattern do a voltage and current waveforms make
Sinusoidal
What are the two mechanisms of damage from contact with electricity
- Cell function disruption
2. Dissipation of electrical energy throughout the body
Name 4 results of electrical cell function disruption?
Contract muscles, alter brain function, paralyze respiration, disrupt normal heart function leading to v fib
The dissipation of electrical energy throughout the bodies tissues meets resistance and raises the temperature causing _____ 
Burns
The severity of electrical shock is determined by these two factors
Amount of current (number of amperes)
Duration of current flow
The two categories of electrical shock are; 
Macroshock and microshock
This refers to a large amount of current flowing through a person which can cause harm or death
Macroshock
This refers to a very small amount of current which may cause damage in an electrically susceptible patient
Microshock
Name the three factors that will affect severity of a shock for a person who completes the circuit 
Skin resistance
Duration of contact
Current density
Threshold of perception
1 mA
Accepted as a maximum harmless current intensity
5 mA
“Let go” current before sustained muscle contraction
10-20 mA
Pain, possible fainting, mechanical injury; heart and respiratory function continues
50 mA
Ventricular fibrillation will start but respiratory center intact
100-300 mA
Sustained myocardial contraction followed by normal heart rhythm; temporary respiratory paralysis; burns of current density is high
6,000 mA
This amperage can cause ventricular fibrillation in electrically susceptible patients
100 micro amps (0.1 mA)
Regarding microshock; Recommended maximum 60 Hz leakage current
10 micro amps (0.01 mA)
Name the two types of electrical power that are supplied—- and which one is likely to be found in OR
Grounded or ungrounded
Ungrounded in OR
The electrical devices themselves in the OR will always be ________
Grounded
Electrical power supply can be ______ or _____, while electrical devices power supply can also be ______ or ______.
Grounded or ungrounded
Grounded or ungrounded
Power delivery in the home is _______, while electrical devices in the home can be grounded or ungrounded 
Grounded
What percentage of electrical accidents in hospitals occur in the OR
40%
The ungrounded power system in the OR is safe through the use of ______ 
IPS, isolated power system
IPS protects from macro shock or microshock?
Macroshock
In order to be safe, Isolated power systems (IPS) require the use of an _______ _________, which acts as an separator between the primary power supply and the isolated circuit.
Isolation Transformer
Isolated power systems impose a very ____ impedance to any current flow to ground
High
P = I^2 x R
What is this equation?
Electrical Power Equation
substituting E with the components of the Ohm’s law
