Brown Cp

Question 1

Interference is

Answer 1

Any electrical disturbance on a metallic structure caused by stray current

Question 2

Stray current is

Answer 2

Current flowing on a structure that it is not part of the intended electrical circuit

Question 3

Dynamic stray currents vary in magnitude and often in direction. These currents can be?

Answer 3

Man made or natural in origin

Question 4

Man made dynamic stray currents come from sources such as

Answer 4

Mine railroads,rail transit system and arc welding operations

Question 5

Tellurium currents are

Answer 5

Naturally occurring dynamic stray currents caused by earths magnetic field by sun spot activity

Question 6

Steady state or static stray current

Answer 6

Maintain constant magnitude and direction

Question 7

Dynamic stray currents are manifested by

Answer 7

Fluctuations in structure-electrolyte potentials readings

Question 8

Electrons are

Answer 8

Particles that carry a negative charge…….also help to hold matter together (kind of like midterm)

Question 9

Voltage (joule/coulomb) or potential

Answer 9

A electromotive force or a difference in potential expressed in volts

Voltage is the energy that puts charges in motion

Question 10

Corrosion uses these units of measure

Answer 10

Volts
Millivolts
Microvolt a

Question 11

1,000 volts is

Answer 11

1 kilovolt

Question 12

1.000 volts equals

Answer 12

1000 millivolts

Question 13

0.100 is

Answer 13

100 millivolts

Question 14

0.010 volt is

Answer 14

10 millivolts

Question 15

0.001 volt is

Answer 15

1 millivolts

Question 16

0.000001 is

Answer 16

1 microvolt

Question 17

EMF is

Answer 17

Electromotive force any voltage

Question 18

E or e is

Answer 18

Voltage across a source of electrical energy (battery,pipe-to soil potential )

Question 19

V or v is

Answer 19

Voltage across a sink of electrical energy (resistor)

Question 20

Current is

Answer 20

The flow of charges along a conducting path is measured in amperes, ……..frequently abbreviated as amps

Question 21

Ampere is

Answer 21

The common unit of current=flow rate of charge of 1 coulomb per second

1 coulomb is the unit of charge carried by 6.24 X 10(18) electron charges

Question 22

1,000 amperes is 1….

Answer 22

1 kilo ampere

Question 23

1.000 is

Answer 23

1000 milliamperes

Question 24

0.100 is

Answer 24

100 milliamperes

Question 25

0.010 amperes is

Answer 25

10 milliamperes

Question 26

0.001 ampere is

Answer 26

1 milliamperes

Question 27

0.000001 amperes is

Answer 27

1 micro ampere

Question 28

Common symbols for current flow are

Answer 28

I, A, mA uA=micro amperes

Question 29

Resistance is

Answer 29

The opposition that charges encounter when moving throu a material

Question 30

The ohm is the common unit of resistance ......letter for ohm is

Answer 30

R or r also the Greek letter omega

Question 31

Resistivity is

Answer 31

The resistance of a conductor of unit length and cross-sectional area ....symbol is Greek letter p

Question 32

Resistivity is constant for a given material and is computed by the formula

Answer 32

P=RxA/L p= Greek letter for resistivity R=resistance in ohm's A=cross sectional area in cm2(centimeter squared) L=length in cm

Question 33

Resistance to current flow is lowest

Answer 33

Low resistivity ( high conductivity) media Short length of current flow Large area of current flow

Question 34

Resistance will be greatest for:

Answer 34

High-resistivity (low conductivity) media Long path length for current flow Small cross sectional area of current flow

Question 35

The electric circuit is

Answer 35

The path followed by an electric current

Question 36

Electrical laws govern the relationship in

Answer 36

Electric circuits

Question 37

Ohm's law is (1v will create 1 current ampere in a circuit having a resistance of 1 ohm

Answer 37

A relationship between the ratio of voltage and current to the resistance of a circuit

Question 38

Power is

Answer 38

The rate at which energy is used by an electrical device

Question 39

Power is measured in

Answer 39

Watts P=EI P=I2R

Question 40

Kirchhoffs voltage law

Answer 40

The sums of the source voltages around any closed loop circuit is equal to the sum of the voltage drops across the resistances in that loop

Question 41

Kirchhoffs current law

Answer 41

The law states as much current flows away from a point as flows towards it

Question 42

In a series circuit

Answer 42

The same current flows in an individual, consecutive path from the source of the voltage through the various loads and back to the source Current is the same everywhere Sum of the voltage add up the the voltage source Total resistance of a series circuit equals the sum of the individual resistance

Question 43

In a parallel circuit....the current..

Answer 43

Divides into a number of separate branches The current in each branch maybe different Each branch may have deferent resistance If you can trace more than one path for current to flow through the circuit.....it's a parallel circuit Total current flowing into and out of the junction point of the branches equals the sum of branch currents (kirchhoffs current law)

Question 44

Ohm's law

Answer 44

V=IR I=V/R R=V/I

Question 45

Unit of measure used in conjunction

Answer 45

Volt, Ampere,Olm's

Question 46

Parallel circuit

Answer 46

Total of current in each leg is equal to the total current B: voltage across each resistor is equal to net supply voltage

Question 47

Metals that corrode under low and high pH levels are termed

Answer 47

Amphoteric