100% Correct Verified Answers
Which is not a primary reaction at the anode?
A. Metal oxidation
B. Oxygen evolution
C. chloride evolution
D. Hydrogen evolution - ✔✔✔ - d. Hydrogen evolution
Which of the following will decrease cathodic protection current requirements?
A. Increased ph
B. Increased oxygen
C. Increased temperature
D. Increased agitation - ✔✔✔ - a. Increased ph
A galvanic anode system is not normally suitable in which of the following conditions?
A. When a small amount of current is required.
B.in high soil resisitivity
C.for localized protection
D.for interference mitigation. - ✔✔✔ - b. In high soil resistivity
The purpose of the galvanic anode backfill is not to
A. Prevent passivation of the anode
,B. Create uniform corrosion of the anode
C. Passivate the anode
D.provide a low resistivity environment around the anode. - ✔✔✔ - c. Passivate the anode
The elements of a galvanic cathodic protection system in soil includes which of the following?
I. Active material
Ii. Noble structure
Iii. Carbon backfill
Iv. Wiring - ✔✔✔ - i, ii, and iv only
An impressed current system is not normally practical under which of the following conditions
A. With very small current requirements
B. For protection of poorly coated and bare structures
C. In high soil resistivity
D. Inside water storage tanks - ✔✔✔ - a. With very small current requirements
Rectifier components could include which of the following?
I. Transformer
Ii. Photovaltaic cells
Iii. Thermopile
Iv. Silicon diodes - ✔✔✔ - i and iv only
Which of the following dc power supplies are commonly used to charge batteries that in turn
provide cathodic protection current?
I. Thermoelectric genorators
,Ii. Solar
Iii. Wind-driven generator
Iv. Saturable reactor - ✔✔✔ - ii and iii only
A transformer will
A. Change ac to dc
B. Increase the dc voltage only
C. Decrease the ac voltage only
D. Increase or decrease the ac supply voltage - ✔✔✔ - d. Increase or decrease the ac supply
voltage
If the primary ac voltage is 100 volts ac, and there are 100 primary windings with 200
secondary windings, what is the the secondary voltage?
A. 25 volts ac
B. 50 volts ac
C. 100 volts ac
D. 200 volts ac - ✔✔✔ - d. 200 volts ac
(100 x 200) / 100 = 200 volts ac
With a single diode installed in series with an ac voltage source the results will be
A. Half wave ac voltage
B. Halfwave dc voltage
C. Full wave ac voltage
D. Full wave dc voltage - ✔✔✔ - b. Halfwave dc voltage
Full wave rectification can be achieved with
, I. A four diode bridge circuit.
Ii. A center tap configuration.
Iii. One silicon-controlled rectifier
Iv. Two silicon-controlled rectifiers and two diodes in a bridge - ✔✔✔ - i, ii, and iv only
What is the purpose of a "free wheeling" diode?
A. To prevent latching of the scr
B. To improve efficiency of the rectifier
C. To convert ac to dc
D. To increase or decrease the ac voltage - ✔✔✔ - a. To prevent latching of the scr ???
The advantage of three phase rectifiers over single phase rectifiers is that they
A. Are more efficient
B. Have lower initial cost
C. Are easier to troubleshoot
D. Are easier to adjust - ✔✔✔ - a. Are more efficient
Which dc power supply converts heat energy directly to electrical energy?
A. Transformer-rectifier
B.solar
C. Thermoelectric generator
D.wind-driven generator - ✔✔✔ - c. Thermoelectric generator
A constant potential rectifier provides a constant