feb test

When in operation, a crane must be kept a minimum distance of ___ feet from power lines of 50 KV or less. Select one: a. 10 b. 8 c. 12 d. 6

10

a non-linear load produces current waveforms that ___ conform to the wavelengths of the applied voltage A. does not B. does

A. does not

a harmonic is a sinusoidal waveform with a frequency that is a integral multiple of the fundamental 60 Hz frequency. A. True B. False

B. False

A buck-boost transformer cannot be used as an isolating (insulating) transformer to supply power to low voltage control circuit. Select one: a. True b. False

False

Buck-boost transformers can be used for voltage drop correction, but only if the load is constant. Select one: a. True b. False

False

If the coils of a buck-boost transformer are connected in parallel the voltages are added together. Select one: a. True b. False

False

There are only two types of cranes. Select one: a. True b. False

False

When signaling a crane, any hand signals can be used as long as all employees agree to the method. Select one: a. True b. False

False

Cranes are used to lift and place ___.I. materials II. persons III. tools Select one: a. I and II only b. II and III only c. II only d. I only e. I and III only

I and III only

Cranes, as with all other types of equipment, can be operated only by ___ persons.I. qualified II. authorized III. trained Select one: a. II only b. II and III only c. I only d. I and III only e. III only

I and III only

The most common types of crane accidents involve getting caught in moving structures and ___.I. cave-ins II. tipovers III. electric lines Select one: a. III only b. I and III only c. II and III only d. II only e. I only

II and III only

An autotransformer has windings that are electrically connected to each other. Select one: a. True b. False

True

Never stand or walk under any load suspended by a crane. Select one: a. True b. False

True

Where the circuit voltage is 208 volts, a buck-boost transformer can be used to operate a load that is rated to operate at 240 volts. Select one: a. True b. False

True

You should not touch or lean against a crane at any time. Select one: a. True b. False

True

The exact ___ of all underground utilities must be determined prior to the opening of any excavation. Select one: a. location b. dimensions c. routing d. depth

a. location

computers vfds and welders are ___ loads a. nonlinear b. linear c. inductive d. resistive

a. nonlinear

Most states have a ___ center to notify the utilities of your planned excavation. Select one: a. one-call b. one-stop c. data d. drop-off

a. one-call

triplen harmonics are odd multipliers of the ___ harmonic a. 5 b. 3 c. 4 d. 2

b. 3

a bolted fault is a fault that is very close to the power source a. True b. False

b. False

heat losses are measured in ___ a. Volts b. Watts c. amperes d. ohms

b. Watts

K-rated transformers ______ reduce the root issue of harmonic currents or power quiality issues a. do b. do not

b. do not

When buck-boost transformers are connected to ___ the input voltage, the primary and secondary voltages are additive. Select one: a. boost b. buck

boost

Accidents involving excavating and trenching contribute to an average of ___ deaths per year. Select one: a. 30 b. 30,000 c. 200 d. 2,000

c. 200

If you are working in a trench ___ feet or more in depth, you must have a means of egress within 25 feet of where you are working. Select one: a. 6 b. 3 c. 4 d. 5

c. 4

is the current limiting characteristics of a transformer a. Frequency b. Power c. Impedance d. Voltage

c. Impedance

Many workers ___ involved with excavation work. Select one: a. are not trained in the hazards b. take deadly risks while c. either a or b d. neither a nor b

c. either a or b

If 120-volt loads are required to be connected to a delta transformer, one of the three output coils has a ___ so that two 120-volt outputs are available. Select one: a. high-leg b. dead man's leg c. stinger d. center-tap

center-tap

A broad knowledge of soils and soil types is necessary to be able to ___ the hazards involved in excavating. Select one: a. quantify b. know c. count d. identify

d. identify

In a corner-grounded delta, the grounded conductor is referred to as the ___. Select one: a. stinger b. dead man's leg c. center-tap d. high-leg

dead man's leg

A ___ connection requires that the single-phase transformers be interconnected so that X1 of one transformer is connected to X2 of the next. Select one: a. single-phase b. wye c. delta d. all of these

delta

If a transformer has a delta primary and a wye secondary, the transformer is referred to as a ___ transformer. Select one: a. delta-delta b. delta-wye c. wye-delta d. wye-wye

delta-wye

Working in excavations requires the use of ___ if the excavation is not made in stable rock. Select one: a. shoring b. sloping c. benching d. protective shields e. any of these f. none of these

e. any of these

When transformers are installed to adjust voltage for a customer's needs, they can be configured to ___. Select one: a. step down the voltage b. step up the voltage c. either of these d. neither of these

either of these

In a three-phase four-wire delta system, the B-phase conductor is known as the ___ and is connected to the middle busbar in the panel. Select one: a. grounded conductor b. high-leg c. corner ground d. center-tap

high-leg

In a three-phase transformer, if a voltage higher than the nameplate rated voltage is applied to the primary, a voltage ___ the nameplate rated secondary voltage will be delivered to a load. Select one: a. the same as b. lower than c. higher than

higher than

When the supply voltage is higher or lower than the nameplate rated primary voltage of a transformer ___. Select one: a. it will result in a ground fault b. it will result in a higher or lower-than-nameplate rated secondary voltage c. it will require installing the transformer in a well-ventilated area d. it will have no effect on the ouptput voltage

it will result in a higher or lower-than-nameplate rated secondary voltage

A(n) ___ delta is a variation of a three-phase, four-wire system that only utilizes two transformers. Select one: a. closed b. open c. corner-grounded d. ungrounded

open

The connected load on the secondary of a transformer causes current to flow in the ___. Select one: a. primary conductors b. secondary conductors c. primary coils d. all of these

primary conductors

When buck-boost transformers are connected to buck the input voltage, the primary and secondary voltages are ___. Select one: a. subtractive b. additive

subtractive

When equipment, a system, or a circuit has a delta or wye designation, the equipment, system, or circuit is ___. Select one: a. single-phase b. three-phase c. either of these d. neither of these

three-phase