Electrostatics, Electric Charges, and Circuit Fundamentals in Physics

______________ is the branch of physics that deals with stationary or resting electric charges.

electrostatics

What type of current is this

direct

Another name for resting charges is

potential energy

What are the two types of electric charges

positive (protons) and negative (electrons)

The addition or subtraction of electrons from an object is termed

ionization

Name the three means of electrification

Friction, contact, and induction

Electrification by means of friction

the removal of electrons from one object to another by the process of rubbing

Example of friction electrification

rubbing a balloon on hair, causing hair to stand up

Electrification by means of contact

When an object has too many electrons, it will give them up to another object, causing the second object to become electrified (with touch)

Example of contact electrification

shocking someone through touch

Electrification by means of induction

The presence of a charged object near a neutral conductor will force (or induce) electrons within the conductor to move

Example of induction electrification

electrons jumping from one conductor to another (transformers)

Name three means of inquiring contact electrification within the radiology department

Sliding a patient over on a slider board, shuffling your feet while walking during low humidity times (winter time), and step-up / step-down transformers

Nonconductors (insulators) examples

paper, glass, wood, or plastics

Conductor examples

metals (silver, gold, Al, and copper)

Semiconductor examples

silicon or germanium (used in computer chips)

Surrounding every charged body there is a region of force around it termed

electric field

Which type of particles within an atom can only cause electrification?

Electrons

Define grounded

a safety mechanism that connects a circuit or device directly to the earth using a physical conductor. It acts as an escape route, providing a safe path for stray or excess electricity to dissipate into the ground. Grounding out excess amount of amperage

What does this symbol stand for?

Grounded

Name the five laws of electrostatics

(1) Repulsion // attraction: like charges repel and opposites attract, (2) The measurement of two points for electrical charges (Inverse square law & Coulomb's law), (3) Distribution: electric charges reside only on the external surfaces of conductors, (4) Concentration: the concentration of charges on a curved surface of a conductor is greatest where the curvature is greatest (focal track on anode), (5) electrons only move on a conductor (from - to +)

Which law demonstrates the inverse square law?

Law 2, stating that "electrostatic forces b/t 2 charges are directly proportional to the product of their quantities and inversely proportional to the square of the distance"

What is the formula for coulomb's law?

F = (q1q2)/r2

Coulomb's Law demonstrates that the

closer two charges are, the stronger the force b/t them

What is an electroscope?

An early scientific instrument used to detect the presence and magnitude of an electric charge on a body. Operating on the principle that "like charges repel"

What natural phenomenon is considered the largest factor on earth for static discharge?

Lightning

The science of electric charges in motion is known as

electrodynamics

Name the four conditions in which an electric current can run a consistent flow of charged particles

In a vacuum, in a gas, in an ionic solution, and on a metal conductor

Give an example of an electric current running a consistent flow of charged particles in a vacuum

XR tube

Give an example of an electric current running a consistent flow of charged particles in a gas

neon lights

Give an example of an electric current running a consistent flow of charged particles in an ionic solution

contrast media // human body

Give an example of an electric current running a consistent flow of charged particles on a conductor

wiring to our XR equipment

Which direction do the electrons flow?

Negative to Positive

________ __________ is defined as the path over which the current flows

Electric current

Name five different sources of electric current

batteries, generators, solar energy, nuclear power plants, wind/hydroelectrical/geothermal

Batteries convert ________ energy to ________ energy

chemical; electrical

Generators convert ________ energy to ________ energy

mechanical; electrical

What does DC current mean?

Direct current (only + wave; lots of heat).

What does AC current mean?

Alternating current (wave form that continuously goes from + to - and - to +; cools throughout cycles)

Name the three factors of an electric circuit

Voltage (v), Amperage/Current (i), and Ohms/resistance (r)

Define potential difference.

the stored energy or the ability to do work

What is the unit for potential difference?

Volt

What does EMF stand for?

Electromotive force

Define current.

The amount of electric charge flowing per second (quantity)

What is the unit for current?

Amperage

What is resistance?

The property that opposes or hinders the flow of electric current without slowing it down (at the speed of light)

What is the unit of resistance?

Ohms

What are the four factors that influence resistance?

A. Material, B. Length of conductor, C. Cross-sectional diameter, D. Temperature

For resistance, the higher the temperature, the ______ resistance (think of running in heat)

more

The larger the diameter, the ______ resistance

less (more electrons can travel if it is a thicker wire)

The longer the length of the conductor the ______ resistance

more

What is the formula for ohms law?

R (resistance/ohms) = v (voltage) / i (current)

What is the resistance of a circuit, using the ohms law, when the current is 24A and the potential difference is 360V?

360 v / 24 a = 15 ohms

What is the voltage of a circuit carrying a current of 35A and having a resistance of 6 ohms?

35 a x 6 ohms = 210 v

What are the two types of chemical devices that can give off electric current?

Cells or batteries

What type of current does a battery have (AC/DC)?

DC

Current only flows when a switch is

closed

What instrument measures the amount of voltage on a line?

Voltmeter

What instrument measures the amount of amperage on a line?

Amp meter

Which instrument will give you the same readout no matter where it is placed on a series circuit?

Amp meter

A ____________ circuit is an electric circuit whose component parts are arranged end to end

simple series

A ________ circuit is an electric circuit whose component parts are connected by branches off of the main circuit

parallel

What is the formula for resistance on a series circuit?

RT = R1 + R2 + R3

What is the formula for voltage on a series circuit?

VT = V1 + V2 + V3

What is the formula for current on a series circuit?

IT = I1 = I2 = I3

A series circuit contains 3 resistors, a blow dryer 12 ohms, a curling iron 8 ohms, and the radio of 16 ohms. If the voltage is 110 V, what is the total resistance?

12 ohms + 8 + 16 = 36 ohms

A series circuit has 20 as the total amount of resistance and 250V. What is the current for that line?

250v/20ohms = 12.5A

If the current is 12 A and the total resistance is 20 ohms, what is the voltage for the circuit?

12A x 20ohms = 240V

What is the formula for voltage in a parallel circuit?

VT=V1=V2=V3=V4

What is the formula of power?

P = IV (power = current x voltage)

What is the unit for power?

Watt

What is the power rating, in kilowatts of an x-ray generator capable of 800 milliamperes at 100 kilovolts?

800mA/1000 = 0.8A x 100kV = 80kw

The current produced by this symbol goes to the

anode side

What does this symbol regulate

mA selector, cathode heat production, and large/small filament

What does the following symbol convert

AC to DC

This symbol is known as a

variable resistor

What type of current does this symbol produce

AC

What does the following symbol do

steps up the voltage

This symbol is known as a

step down transformer

What does the following symbol do to the amperage

sends it to the ground

Where does the following device need to be located in the electric circuit

parallel to the power source

Where can this symbol be placed in the electric circuit

right after the power source off to the side // anywhere on the line

Does this image allow for electrons to flow

no

What type of charge does this device store

mAs

What type of current does this symbol create

direct current

Which of the following are superconductors

titanium and niobium

A motor is a device that converts

electrical to mechanical energy

Current (the wave) flows from

positive to negative

Which of the following is NOT a means of conducting electrical current: in a vacuum, in a gas, on the detent button, or on a metal conductor

on the detent button

The x-ray tube converts electrical energy into what type of energy

Heat (99%) and electromagnetic

What type of rock will produce electric charges when rubbed with a wool cloth

Amber (by friction)

Who was the scientist who studied electrostatic charges, created the distinction between insulators and conductors, and invented the battery

Ben Franklin

What method of electrification deals with electric charges jumping from one conductor to another without contact?

Induction (transformers use this)

The electric field goes inward or outward for a proton?

outward

The electric field goes inward or outward for an electron?

inward

Which type of material does not allow electrons to flow?

Insulators