Electrotherapy Notes: Physics of Electricity

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Questions and Answers

What particle in an atom has a positive charge?

Proton (correct)

Electron

Neutron

Nucleus

A neutral atom has an equal number of protons and electrons.

True

What is the universal color for anode electrodes?

Green

Red (correct)

Blue

Black

What happens to a negatively charged body when it seeks neutrality?

It loses electrons Signup and view all the answers

What is the definition of a conductor?

Materials that can transmit electrical current. Signup and view all the answers

A/an ______ ion results from loss of electrons in an atom.

cation Signup and view all the answers

A/an ______ ion results from gain of electrons in an atom.

anion Signup and view all the answers

Which of the following statements about electric fields is true?

Lines of force are straight. Signup and view all the answers

What is the quantity of electricity measured in?

Coulomb Signup and view all the answers

What characteristic defines a step-up transformer?

It produces a higher voltage from a lower voltage. Signup and view all the answers

How does a variable transformer allow for voltage adjustment?

Through a knob that alters the number of coils in the primary coil. Signup and view all the answers

What happens to the electric field when a nucleus is gained or lost?

It creates an electric field. Signup and view all the answers

Which property of lines of force indicates their behavior in different materials?

They pass more easily through conductors. Signup and view all the answers

What is the function of a fuse in an electrical circuit?

To melt and break the circuit in case of over-intensity current. Signup and view all the answers

What effect does a positive charge have on lines of force?

They concentrate nearest to the positive charge. Signup and view all the answers

What distinguishes a static transformer from other types?

It outputs a fixed voltage without changes. Signup and view all the answers

What is a characteristic of conductors?

They can transmit electrical current. Signup and view all the answers

Which type of transformer consists of a single coil with multiple contact points?

Autotransformer Signup and view all the answers

When an atom gains electrons, what type of ion is formed?

Anion Signup and view all the answers

What happens to the voltage in a step-down transformer?

The voltage is decreased from a higher to a lower level. Signup and view all the answers

How is capacitance of an object quantified?

In Coulombs Signup and view all the answers

What potential risk does a low melting point material in a wire pose?

It can melt and break the circuit when overheating. Signup and view all the answers

What impact does adjusting the number of coils in the primary coil of a variable transformer have?

It varies the output voltage based on the primary configuration. Signup and view all the answers

If an atom loses electrons, what charge does it acquire?

Positive charge Signup and view all the answers

Which of the following statements is true regarding the quantity of electricity?

1 Coulomb is equal to 6.26 x 10^18 electrons. Signup and view all the answers

Which type of switch operates by pushing a button?

Push Button Signup and view all the answers

What type of electric circuit allows current to follow an unintended path?

Short circuit Signup and view all the answers

What color is typically associated with the neutral wire?

Blue Signup and view all the answers

In terms of electric shock, what bodily state increases current intensity?

Wet or damp skin Signup and view all the answers

Which of the following describes a toggle switch?

Similar to a rocker switch Signup and view all the answers

Which factor does NOT contribute to the severity of an electric shock?

Type of insulation Signup and view all the answers

What happens to the electric current if it completes its circuit via a shorter distance?

It may cause a short circuit Signup and view all the answers

What happens when the live wire contacts the metal casing of an appliance?

Current passes to the earth ground Signup and view all the answers

Which is the correct relationship between current and shock severity?

Higher intensity leads to a more severe shock Signup and view all the answers

What is the primary purpose of the earth/ground wire in electrical systems?

To protect against short circuits Signup and view all the answers

What is the relationship between denervation and the response intensity required for stimulation?

Denervated structures require greater intensity to stimulate compared to innervated structures. Signup and view all the answers

In the context of electrical stimulation, what does pulse interval typically relate to?

The time between successive stimulation pulses. Signup and view all the answers

How does the structure's accommodation affect stimulation when considering denervation?

If a structure accommodates, increasing intensity is needed to stimulate it. Signup and view all the answers

What shape of the stimulation pulse may indicate the probable pulse duration suitable for treatment?

Sawtooth wave Signup and view all the answers

When dealing with an unknown structure, what is the recommended approach regarding intensity?

Start with the least intensity and adjust as needed. Signup and view all the answers

What is the purpose of the grounding wire in electrical devices?

To divert current to the ground and reduce the risk of shock. Signup and view all the answers

Which correctly describes the difference between AC and DC current?

AC current flows to and fro while DC current flows continuously in one direction. Signup and view all the answers

What happens when the switch is turned off?

A spring separates the socket and blades, opening the circuit. Signup and view all the answers

Which of the following is true about a closed circuit?

It allows current to flow through the circuit. Signup and view all the answers

What physical phenomenon can occur if the switch is separated slowly?

Arcing of the current and potential burning of metal contacts. Signup and view all the answers

Which statement accurately describes a two-pronged outlet?

It is designed for devices that do not require grounding. Signup and view all the answers

How does a switch primarily operate?

By opening and closing the circuit to control current flow. Signup and view all the answers

What effect does a circuit breaker have when it is tripped?

It interrupts the current flow to protect the circuit. Signup and view all the answers

Study Notes

Atoms and Their Structure

Atoms are the smallest indivisible particles that comprise all matter.
An atom consists of a nucleus and electrons.
The nucleus contains protons (positively charged) and neutrons (neutrally charged).
Protons determine the atomic number of an atom.
Neutrons affect atomic mass and are present in equal numbers with protons.

Proton and Neutron Properties

Protons cannot be removed from the nucleus; they define the element's identity.
Neutrons contribute to atomic mass but do not affect charge.

Electrons and Their Behavior

Electrons are negatively charged and revolve around the nucleus in defined shells or quantum shells.
Electrons can be gained or lost, impacting an atom's charge and creating an Electric Field.

Electric Charge and Neutral Atoms

A neutral atom has an equal number of protons and electrons.
Cations are positively charged ions formed by the loss of electrons.
Anions are negatively charged ions created by the gain of electrons.

Electrodes and Their Functions

Anode:
- Attracts anions (negatively charged ions).
- Represented by the color red.
- It is the positive electrode.
Cathode:
- Attracts cations (positively charged ions).
- Represented by the color black.
- It is the negative electrode.

Electricity Fundamentals

Electricity is a form of energy involving the flow of electric charge.
A charged body seeks to attain neutrality by gaining or losing electrons.
An electric field is generated during charge transfer, consisting of lines of force.

Properties of Electric Fields

Lines of force are straight and travel more easily through conductors than insulators.
Lines concentrate closer to other objects, exerting a greater influence.
Lines of force travel from negative to positive zones.

Conductors and Their Functionality

Conductors are materials that can transmit electrical current due to their loosely held outer electrons.
Conductors facilitate the flow of electricity efficiently.

Quantity of Electricity

Quantity of electricity is measured in Coulombs.
1 Coulomb (C) is equivalent to approximately 6.26 x 10^18 electron charges.

Switch Types and Functions

Push Button: Activates device by pressing, can turn on/off.
Slide Switch: Sliding action turns the device on/off.
Rocker Switch: Common for lights, with symbols indicating on (vertical line) and off (0).
Rotary Switch: Device activates through rotation.
Toggle Switch: Similar to rocker, functions like a small joystick.

Electrical Safety and Short Circuits

Short Circuit: Occurs when electricity travels along unintended paths.
Pathway: Normal flow is live wire → outlet → machine → neutral wire.
Shock: Sudden current flow can cause painful stimulation, affected by current intensity and resistance.
Severity Factors: Higher intensity, lower resistance, and passing through delicate body parts increase shock severity.
Alternating Current (AC): Provides higher risks of shock compared to Direct Current (DC).

Atomic Structure and Ions

Neutral Atom: Equal number of protons and electrons.
Cations (+): Formed by losing electrons (positive charge).
Anions (−): Formed by gaining electrons (negative charge).

Conductors and Electricity

Conductors: Materials that transmit electric currents due to loosely held outer electrons.
Quantity of Electricity: Measured in Coulombs; 1 Coulomb = 6.26 x 10^18 electron charges.

Transformers

Step-Up Transformer: Increases voltage (60 turns primary, 120 turns secondary; voltage rises from 100V to 200V).
Types of Transformers:
- Static Transformer: Voltage output remains constant, no changes.
- Variable Transformer: Adjustable output via a knob to change coil number.
- Autotransformer: Single coil with multiple contact points for automatic voltage adjustment.

Circuit Protection Devices

Fuse: Melts to break circuit and prevent damage from overcurrent.
Circuit Breaker: Cuts off circuit during excessive current flow to prevent shocks and equipment damage.

Electrical Outlets

Two Pronged Outlet: Has larger neutral terminal and smaller live terminal ensuring proper current flow.

Current Types

AC (Alternating Current): Current flow reverses direction periodically, characterized by changing polarity.
DC (Direct Current): Unidirectional flow of electrons, preferred for consistent voltage supply.

Electrical Wiring and Switches

Switch Functionality: Opens or closes circuits; open circuit stops current flow, closed circuit allows it.
Types of Switches: Feature metal blades fitting into sockets to control current flow.
Pulse Intensity: Varies for innervated versus denervated structures during stimulation.

Additional Considerations

Pulse Interval: Suggested pulse duration for treatment should be 2-3 times the duration of the pulse.
Safety in Stimulation: Lowest intensity recommended to assess innervation status and avoid damage during treatment.

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Description

Explore the fundamentals of electrotherapy in this quiz focused on the physics of electricity and its components. Understand concepts such as electrodes, their functions, and the behavior of electric charges. This material serves as an essential introduction to electrotherapy principles.