Chapter 1 Flashcards
Basic Electricity
_______ is the total opposition that a circuit presents to alternating current similar to resistance in a dc circuit
impedance
electrons
particles of an atom that carry a negative charge
______ is the flow of charge along a conducting path and is measured in amperes.
current
Do these qualities least or greatest resistance?
- high resistivity low conductivity media
- long current path
- small cross sectional area of current path
greatest
What are the common DC voltmeter ranges?
200 mv current shunt readings 2 volts structure to electrolyte 20 volts structure to electrolyte and rectifier 200 volts rectifier voltage output 1000 volts unknown voltage
What is ohm’s law?
V=IxR
V/I=R
V/R=I
_______ is the electromotive force or difference in potential expressed in _______
Voltage or potential, volts
Typical uses for ammeter?
- rectifier output current
- test current
- bond current
AC can be converted to DC by using a
rectifier
______ circuit
- V drop across each branch is the same
- current divides into a number of separate branches
- total current entering equals total current leaving
parallel circuit
electronic circuitry with analog display
hybrid meter
Kirchoffs law current
current entering a junction equals current leaving a junction
How to determine current flow?
If current enters on the positive terminal a positive sign will be displayed. if current enters on the negative terminal a negative sign will be displayed
ohm meter is used for
used for continuity testing
Conductivity is
the inverse of resistivity and is the measure of the ability of a material to pass current
______ blank current changes polarity and direction with time.
alternating current.
AC changes polarity and direction 100 or 120 times per second
_____ currenct has constant polarity and direction
direct
________ is the force that puts charges in motion
voltage
The rate to which energy is used by an electrical device is called
Power
State kirchoffs law of voltage
sum of voltage drops must equal total voltage
__________ is is a DC moving coil-type movement in which an electromagnetic core is suspended between the poles of a permanent magnet.
Darsonval movement
Multimeter: Volt meter
What are the units?
HOw is it used to take a reading?
What is between leads?
Volts, connected across the circuit element,
high resistance
______ are used to increase or decrease AC voltage or to isolate incoming AC source form outgoing
transformer
_________ is the property of a conductor relating its resistance to geometry
resistivity
A length of pipe or cables and resistance between a single galvanic anode and structure are examples of _____ circuit.
series
Do these qualities least or greatest resistance?
- low resistivity high conductivity media
- short length of current path
- large cross sectional area of current
least
how is an ammeter used to take a reading
connected in series in the circuit
