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S1-Q26.) In the following symbol, to which terminals is the AC connected?

1

3 4

2

a.) 1 and 3
This would cause a dead short on each half cycle.
b.) 4 and 2
This would cause a dead short on the same half cycle as above.
c.) *1 and 2
Correct. On the positive alternation AC would run through the diodes located between 1 and
3. The diode between 3 and 2 is reverse biased at this point and would block the AC. AC would
then travel through the load and back to the source through the diode between 4 and 2. The
diode between 4 and 1 would block as it would be reverse biased also. On the negative
alternation, the diodes between 2 and 3 passes, 3 and 1 block, travels out 3 through the load, 4
to 1 passes back to the source and 4 to 2 blocks.
d.) 3 and 4
This is where the load must be connected for proper rectification.

S1-Q27.) Which of the following wires has the greatest cross-sectional area?

a.) 0 AWG
The American Wire Gauge format specifies that the smaller the number, the larger the cross sectional
area. Once the wire gauge reaches 0, to go larger, they have added more zeros rather than using a
fractional number. So while 0 is large there are three larger gauged wires.
b.) *00 AWG
Correct. This answer contains the most zeros of the answers and so denotes the largest wire
gauge of these selections. There are two larger gauged wires 000 (three ought) and 0000 (four
ought). After 0000, wire is measured in Circular Mils (MCM). This is a function of the cross
sectional area.
c.) 4 AWG
The American Wire Gauge format specifies that the smaller the number, the larger the cross sectional
area. There are several smaller, whole numbers.
d.) 20 AWG
The American Wire Gauge format specifies that the smaller the number, the larger the cross sectional
area. There are several smaller, whole numbers. This is a relatively small gauge wire.

S1-Q28. ) When referring to a shielded cable, which is NOT a correct statement about terminating that shield?

a.) Terminate one end only
To avoid creating a “ground loop”, only one end is terminated on a shield.
b.) Terminate to ground
Noise must be shunted to ground.
c.) *Terminate both ends to ground
Correct. Both ends should never be terminated to ground. Noise can enter the shielding, travel to
ground, through the machine’s metal back to the other end of the shield. This is known as a ground
loop and may be detrimental to machine operation.
d.) Shields should never be left un-terminated
Un-terminated shields can offer no protection from outside forces. They must always be terminated to
ground.

EGSA Apprentice Certification Program Study Guide - Page 64