# Day 3 Flashcards

1
Q

Which reference electrode is field rugged and designed for use in seawater

A. Silver silver chloride

B. Hydrogen

C. Copper copper sulfate

D. Saturated calomel

A

A

2
Q

When measuring a structure to electrolyte potential it is important to eliminate IR drop across which of the following connection points

A. through the soil

B. metallic path

C. reference electrodes

D. soil contact

Choose all that apply

A

A
B
C
D

3
Q

Which of the following instruments can measure and store potential changes over time

A. Volt meter

B. Data logger

C. Power meter

D. Ohmmeter

A

B

4
Q

If a structure to electrolyte potential of -.850 volts to copper sulfate is measured which of the following conversions to another electrode is correct

A. +266 mV to zinc

B. -.910 V to silver silver chloride

C. -72 mV to calomel

D. +.780 V to calomel

A

A

5
Q

To calculate resistivity using the Wenner 4 pin method the following measured value is used

A. voltage

B. current

C. resistance

D. power

A

C

6
Q

A voltage of .02 V across a 50 mV and 10 Ampere shunt indicates a current of

A. 0.004A

B. 0.1A

C. 4.0A

D. 50A

A

C

7
Q

What is the current through a 50 mV and 20 Ampere shunt with a measurement of 20 mV

A. 50A

B. 8A

C. 50mA

D. 8mA

A

B

8
Q

In the equation used to calculate the resistivity using the Wenner 4-pin method, R represents:

A. Resistivity in Ohms

B. Resistivity in Ohm-cm

C. Resistance in Ohms

D. Resistance in Ohm- cm

A

C

9
Q

If a resistance of 3.5 Ohms was measured using the 4-pin Wenner method and spacing between the pins as indicated below, what is the resistivity?

C1 2m P1 2m P2 2m C2

A. 44 Ohm-cm

B. 132 Ohm-M

C. 4397 Ohm-cm

D. 13,192 Ohm-cm

A

C

10
Q

Using the 4 pin Wenner method as connected below what resistance measurement could be expected if the soil resistivity is 1000 Ohm-cm

C1 1m P1 1m P2 1m C2

A. <0 Ohms

B. 3.1 Ohms

C. 9.4 Ohms

D. 1.59 Ohms

A

D

11
Q

Which is a more active metal?

A. a copper rod in copper sulfate solution

B. corroded steel in freshwater

C. new steel and freshwater

D. a copper sheet in freshwater

A

C

12
Q

Compared to zinc and anodes magnesium anodes in high resistivity soil

A. will deliver a higher current

B. will deliver a lower current

C. will have a higher efficiency

D. Are less practical

A

A

13
Q

A constant voltage rectifier is normally adjusted by changing

A. primary transformer taps

B. series resistor

C. parallel resistor

D. secondary transformer taps

A

D

14
Q

Typically the cathodic protection rectifier will have a

A. transformer

B. rectifying element

C. voltmeter and Ammeter

D. ohmmeter

Choose all that apply

A

A
B
C

15
Q

In a galvanic anode installation the

A. buried wire between the anode and structure receives cathodic protection

B. wire between between the structure and anode will corrode at breaks in the insulation

C. structure connection will corrode if exposed to the electrolytes

D. plastic bag must be left on during installation

A

A

16
Q

Compared to magnesium anode’s zinc anodes

A. have a lower efficiency

B. have a more noble open circuit potential

C. will not passivate in soils with carbonates

D. will not change with temperature

A

B

17
Q

Compared to zinc anodes of the same size and shape magnesium anodes

A. will deliver a higher current in high soil resistivity

B. will deliver a lower current in low soil resistivity

C. will operate at a higher efficiency in a high resistivity soil

D. must be larger to deliver more current in a high resistivity soil

A

A

18
Q

If the external circuit resistance of a constant voltage rectifier increases by two times the following will occur

A. the voltage will increase by two times

B. the voltage will be reduced by 1/2

C. the current will increase by two times

D. the current will be reduced by 1/2

A

D

19
Q

In and impressed current system

A. the negative terminal of the DC power source is connected to the anodes

B. the positive terminal of the DC power source is connected to the anodes

C. the positive terminal is connected to the structure to be protected

D. it is not critical to which terminal of the structure is connected

A

B

20
Q

Test stations are to be installed for which of the following purposes

A. to obtain structure to electrolyte potential’s

B. to confirm the effectiveness of underground isolating fittings

C. to confirm isolation of road casings

D. to measure the amount and direction of current in a pipeline

Choose all that apply

A

A
B
C
D

21
Q

Typically a constant voltage cathodic protection rectifier will not have

A. a transformer

B. a transistor

C. a rectifying element

D. voltage taps

A

B

22
Q

Impressed current anode beds may be installed in the following configuration

A. remote shallow vertical anodes

B. remote shallow horizontal anodes

C. deep vertical anodes

D. distributed shallow vertical and anodes

Choose all that apply

A

A
B
C
D