Shared Flashcard Set

Details

Radiographic Physics 1 - Unit 8 & 9
Electrodynamics & Electromagnetism
66
Physics
Undergraduate 3
07/24/2013

Additional Physics Flashcards

 


 

Cards

Term
When 2 charges are positioned close to each other they possess
Definition
electric potential
Term
unit for electric potential
Definition
volt
Term
other names for electric potential
Definition
electric pressure
voltage
potential difference
Term
3 Componets of a simple circuit
Definition
1. current (amps)
2. voltage (volts)
3. Resistance (ohms)
Term
the "force" of electron flow
Definition
voltage/electric potential
Term
Voltage always flows from:
Definition
high negative potantial to low negative potential
Term
Electrodynamics
Definition
electrons in motion
Term
circuit
Definition
the pathway over which electrons flow
Term
conductor
Definition
allows electrons to flow freely
Term
superconductor
Definition
a conductor with very little resistance to electrons
Term
nonconductor
Definition
does not allow electrons to flow; used as an insultor
Term
semiconductor
Definition
sometimes a conductor and sometimes not
Term
parallel circuit
Definition
an electric circuit designed to send electrons through various resistance devices by giving each component its own branch
Term
series circuit
Definition
an electric cirsuit designed to send electrons through various resistance devices by linking them to one another
Term
where do negative charges reside?
Definition
on the surface
Term
Factors influencing resistance
Definition
1. Material - type of conductor; good conductor=less resistance

2. Length of conductor - increased legnth=increased resistance

3. Diameter of conductor - decreased diameter=increased resistance

4. Temperature - increased temp=increased resistance
Term
Name 2 types of circuits
Definition
1. Series
2. Parallel
Term
Ohm's Law
Definition
The voltage across the total circuit or any portion of the circuit is equal to the current times the resistance.

V=IR
Term
In a series circuit, what is contant?
Definition
Current is constant
Term
In a series circuit, what will vary with resistance?
Definition
Voltage will vary with resistance
Term
In a parallel circuit, what is constant?
Definition
Voltage is constant
Term
In a parallel circuit, what will vary with resistance?
Definition
Current will vary with resistance
Term
capacitator
Definition
stores electrical enegery
Term
Who proved a magnetic field can produced electricity?
Definition
Faraday
Term
Who laid the groundwork for a generator?
Definition
Faraday
Term
Capacitance
Definition
the amount of charge stored; Farad is unit of measurement
Term
The amount of charge stored
Definition
Capacitance
Term
Stores electrical energy
Definition
Capacitator
Term
Armature
Definition
a coil wire that acts as a conductor
Term
What kind of "ring" does a DC generator have?
Definition
commutator ring/split ring
Term
The current induced on the armature of a generator will always be _____.
Definition
Alternating Current
Term
1 AC cycle takes place in _______ sec.
Definition
1/60 sec = 60cps
Term
1/2 AC cycle, or one pulse, takes place in _______ sec.
Definition
1/120 sec = 120pps (60+/60-)
Term
Electric Power
Definition
the amount of work current can do
Term
The amount of work current can do
Definition
Electric Power
Term
Unit of measurement for Power
Definition
watt
Term
Power equation
Definition
P=IV
Term
All electrical devices produce _____.
Definition
Heat.
Term
Power Loss Formula
Definition
Power Loss = I^2 R

The amount of heat produced depends on the current the device draws and the resistance of the conductor
Term
Transformer
Definition
Electromagnetic device that allows us to transform the intensity of alternating voltage and current.
Term
A device in which 2 coils are placed near one another without electrical connection. The number of coils differes, causing a change in current in the secondary coil, this serves to either increase or decrease the voltage.
Definition
Transformer
Term
Transformer perform at ____% efficiency.
Definition
98%
Term
Step-Up Transformer
Definition
A transformer that has more turns on the secondary side than the primary side.
Term
Variac
Definition
variable transformer, can step-up or step-down voltage
Term
Electromagnetism
Definition
a branch of physics that deals with the relationship between electricity and magnetism
Term
The branch of physics that deals with the relationship between electricity and magnetism
Definition
Electrodynamics
Term
Experiment Oersted used to link electricty and magnets.
Definition
Compass experiment
Term
Who demonstrated how flux lines arrange themselves around the conductor using DC current?
Definition
Davy
Term
impedance
Definition
The total resistance in an AC circuit (Z)
Term
inductive reactance
Definition
The ability of an alternating current to witch directions, causing the opposing potential difference to induce against the incoming supply of electrons.
Term
3 ways electromagnetic induction can happen:
Definition
1. The magnetic field moves - the magnet moves while the conductor is stationary

2. The conductor moves - the conductor moves while the magnet is stationary

3. magnetic flux changes direction - magnet and conductor remain stationary
Term
Faraday's Law
Definition
The magnitude of induced current depends on 4 factors:
1. the strength of the magnetic field

2. teh velocity of the magnetic field as it moves past the conductor

3. the angle of the conductor to the magnetic field

4. The amount of turns in the conductor
Term
What is the direction of the induced current?
Definition
Opposite to the direction of the action that has induced it.
Term
2 Types of Induction
Definition
1. Mutual Induction - the result of 2 coils being placed in close proximity with a varying current supplied to the first coil, which then induces a similar flow in the second coil.

2. Self Induction - The ability of an alternating current to switch directions, causing an opposing potential difference to induce against the incoming supply of electronsl allows direct current to flow while at the same time hindering alternating current.
Term
Electrodynamics is:
Definition
the study of moving negative charges
Term
Material which allow electrons to move through them easily are termed:
Definition
conductors
Term
Ohm's law is represented mathematically by:
Definition
V=IR
Term
In a prallel circuit, as the resistance increases the:
Definition
Voltage remains constant
Term
The ammeter is a device which measures current and is connected in _____ in the circuite.
Definition
Series
Term
The unit for electrical pressure is:
Definition
Volt
Term
As the length of a conductor increases, the resistance:
Definition
Increases
Term
The total resistance in a parallel circuit is _____ the resistance through each branch of the circuit.
Definition
less than
Term
The fundamental unt=it of electric charge is the:
Definition
Coulomb
Term
______ denonstrated the magnetic flux lines through experimental investigation.
Definition
Davy
Term
Defined as the ease at which a material can be magnetized.
Definition
Permeability
Term
The unit for power is the:
Definition
watt
Supporting users have an ad free experience!