Master Electrician PRETEST QUESTIONS ANSWERED CORRECTLY

Master Electrician PRETEST QUESTIONS ANSWERED CORRECTLY A compressor motor is rated 1HP, 115V, 16 amps. It is connected to a receptacle providing 120 volts with a 100' extension cord. Due to the load conditions, the maximum voltage drop allowed during starting lockedrotor condition is 30% of motor voltage rating. Using 96 amps for locked-rotor current. Resistance equals impendence. Use resistance values in Table 8 & 9. What is the minimum size of uncoated copper? - ANSWER 10 AWG The cross-sectional area of a conductor is decreased by a factor of 4. What is the new conductor's resistance? - ANSWER 4 times resistance The circular mil area of a number 12 conductor is ____. - ANSWER 6530 The cross sectional area of a conductor is compared to a conductor that is four times its area. What is the approximate resistance of the larger conductor compared to the smaller? - ANSWER 1/4 resistance Eighteen, 250 KCMIL, THWN copper conductors are in a rigid metal conduit nipple. What is the minimum diameter in inches permitted by for the conduit? Assume that the conductors are not lead covered and the nipple is 1' in length. - ANSWER 5" What size RMC nipple (18" long) is required for 24, AWG #8 THHN? - ANSWER 1.25" Using Table 4 and Table 5 of the NEC, compute the maximum number of # 10 AWG, Type THHN, copper conductors allowed in 32' run of 1/2" "IMC". - ANSWER 6 What size EMT raceway is required for 24, AWG #6 THHN? - ANSWER 1 1/2" Determine the cross sectional area in square inches for the following combinations of copper conductors: 4-#8 AWG, THHN; 8-#12 AWG, RHW; 6 - #10 AWG, XHHW: - ANSWER 0.5746 SI The number of #12 THW conductors allowed in a 3/4" conduit will be more than the number of #12 TW conductors allowed in a 3/4" conduit. - ANSWER False How many #12 RHW copper conductors (with outer covering) can be placed in a 1" EMT conduit? - ANSWER 9 Five conductors, in a 12" nipple of rigid metal conduit, has a total cross sectional area of 2.5 square inches. What is the minimum trade size conduit? - ANSWER 3" What is the internal diameter of a 1 1/4" liquid tight, flexible non metallic conduit (type LFNC-A)? - ANSWER 1.395" When calculating the maximum number of conductors permitted in a conduit or tubing, all of the same size, the next higher whole number shall be used to determine the maximum number of conductors permitted when the calculation results in a decimal of ___ or higher. - ANSWER .8 According to the NEC, a 1 1/2" nipple with three conductors can be filled to an area of ____ square inches. - ANSWER 1.224 A 2" conduit no more than ___ in length connecting a gutter and a switch case