MASTER OPENBOOK EXAM #4

AC circuit of less than 50 volts shall be grounded under which of the following?

 

I.       Where installed as overhead conductors outside of buildings

II.     Where supplied by transformers if the transformers supply system is ungrounded

III. Where supplied by transformers if the transformer supply system exceeds 150 volts to ground.

• I only

• II only

• III only

• I, II or III

Which of the following conditions must be met for vehicle mounted generators used to supply electrical tools on a construction site?

 

I.       The frame of the generator is bonded to the vehicle frame.

II. The generator supplies cord and plug connected equipment thru receptacles mounted on the vehicle or on the generator.

• I only

• II only

• both I and II

• neither I or II

Distribution systems for mobile home parks shall be ___.

• 120/240v three-phase

• 120/208v three-phase

• 120/240v single-phase

• 120/230v single-phase

Metal oxide surge arrester ratings are based on the magnitude and duration of overvoltage at the arrester location as affected by ___.

 

I. switching surges           II. system grounding techniques  III. phase-to-ground faults

• I only

• II only

• III only

• I, II and III

___ device providing equivalent overcurrent protection in closed-loop power distribution system shall be permitted as a substitute for fuses or circuit breakers.

• Approved

• Listed

• Accessible

• Automatic

A unit or assembly of units or sections, and associated fittings, forming a rigid structural system used to securely fasten or support cables and raceways is a ___.

• flat cable assembly

• wireway

• multioutlet assembly

• cable tray system

___ is the distance measured along the enclosure wall from the axis of the centerline of the terminal to a passing through the center of the opening in the enclosure.

• Offset

• Radius

• Center Point

• none of these

Which of the following is permitted to support a lighting fixture weighing over 50 pounds?

• The screw shell of lamp holder

• A box of fitting that is listed for the weight to be supported

• An outlet box

• Fixture wires #14 and larger

Which of the following statements about junction boxes is/are true?

 

I. all shall have a cover   II. all over 6’ in length shall have conductors cabled or racked

• I only

• II only

• both I and II

• neither I nor II

Branch circuits in a recreational vehicle may be derived from autotransformers if ___.

 

I. the transformer is listed for vehicle use              II. UL and CSA listed and approved

• I only

• II only

• both I and II

• neither I nor II