Kentucky Masters exam Elecric Questions With Complete Solutions

A 120 volt road sign has #6 copper THWN conductors in a 2" PVC conduit. The sign pulls 8 amps and is on a 30 amp breaker. what is the longest distance that the sign can be located from the sub-panel and still be legal? Use k = 12.9 a. 100-200 feet b. 201-300 feet c. 301-400 feet d 401-500 feet correct answer: d. 401-500 A 175 KVA, single phase transformer having a primary voltage of 240 and a secondary voltage of 120 has been installed at a multi-family dwelling. The current available at the primary is ___. Select one: a. 329 amps b. 421 amps c. 625 amps d. 729 amps correct answer: d. 729 amps A 240 volt, 20 amp circuit may supply ___ linear feet of electric baseboard heat. Baseboard heaters being used are rated 240 volts, 250 watts per linear foot. Select one: a. 12 b. 15 c. 16 d. 18 correct answer: b. 15 A 45 kVA 3 phase transformer has 480/277 volts on the primary and 208/120 volts on the secondary. If the secondary side is pulling 47 amps, how many amps will the primary pull? Select one: a. 20 b. 54 c. 94 d. 125 correct answer: a. 20 A bare #4 conductor may be concrete encased and serve as the grounding electrode when at least ___ feet in length. Select one: a. 10 b. 12 c. 20 d. 15 correct answer: c. 20 A cabinet or cutout box if constructed of sheet steel, the metal thickness shall not be less than ___ inch uncoated. Select one: a. 0.053 b. 0.503 c. 0.040 d. 0.373 correct answer: a. 0.053 A device box contains four #10 conductors and four #12 conductors. Assuming each conductor carries current, for the purposes of determining box fill, these conductors are equivalent to ___ cubic inches. Select one: a. 17 b. 18 c. 19 d. 20 correct answer: c. 19 A ground rod is required to be driven a MINIMUM of ___ feet into the soil. Select one: a. 4 b. 6 c. 8 d. 10 correct answer: c. 8 A lighting fixture shall be supported independently of the outlet box when it weighs more than ___ pounds unless the outlet box is listed for the weight to be supported. Select one: a. 6 b. 25 c. 35 d. 50 correct answer: d. 50 A one-family dwelling unit that is at grade level shall have ___ outdoors. Select one: a. one receptacle at either the front or the back b. one receptacle for every 100 linear feet c. one receptacle at the front d. one receptacle at front and one at the back correct answer: d. one receptacle at front and one at the back A portable motor may use an attachment plug and receptacle as the controller provided the motor does not exceed ___ hp. Select one: a. 1/8 b. 1/3 c. 1 d. 3 correct answer: b. 1/3 A recessed incandescent fixture with a solid lens is installed in the ceiling of a clothes closet. This fixture must ___. Select one: a. be installed a minimum of 12" from storage space b. be installed a minimum of 6" from storage space c. be installed a minimum of 24" from storage space d. A recessed fixture is not permitted in a clothes closet correct answer: b. be installed a minimum of 6" from the storage space A service drop over a residential driveway shall have a minimum height of ___ feet. Select one: a. 10 b. 12 c. 15 d. 18 correct answer: b. 12 feet A two pole circuit breaker that may be used for protecting a 3 phase corner grounded delta circuit shall be marked ___. Select one: a. 1ø 120/240v b. 1ø -3ø c. 1ø/2ø/3ø d. 480Y/277v correct answer: b. 1 phase - 3 phase A type of conductor insulation approved for use in both dry and wet locations is: Select one: a. TFE b. THHN c. THWN d. SA correct answer: c. THWN A vertical run of 4" rigid conduit is installed to a height of 250 feet. The conduit contains four #500 kcmil THHN copper