Electrician Practice Tests

Refer : 215.52 (B)( 2)
Total load on a feeder = 480 + 480 + 1.25 * 80 = 1060 VA

Feeder circuit ampere rating = 1060/120 = 8.83 amperes ( 9 amperes)

Refer : Table 220.42
first 3000 VA => 3000 *  100% = 3000
from 3000 – 120000 VA = 1000 * 35% = 350
3000 + 350 = 3350 VA

Refer : 220.43 (A)
For show window lighting the minimum load should be 200 V-A / Linear foot
total load = 10 * 200 = 2000 V-A

For lighting load per sq.ft = 3 Watts
so total lighting load = 2000 * 3 = 6000 watts
total load on single branch circuit at 120 volts = 120 * 15 = 1800 watts
So minimum branch circuits = 6000/1800 = 3.3 (4 without any over load)

Refer : NEC 220.14(I)
Expect dwelling unit, branks and office building (with some conditions), in all other units the calculated load is not less than 180 volt-amperes for each single or multiple receptacles on one yoke.
So total calculated load = 20 * 180= 3600 volt-amperes.

Refer : 220.14 (I)
Minimum calculated load of receptacle other than dwelling unit is 180 volt-ampere
So  ampere rating at 120 volts source voltage = 180 / 120 = 1.5 amperes

Total receptacles permitted on 20 ampere breaker = 20/1.5 = 13. ( breaker should not be overloaded)

Refer : NEC 220.14 (I)
If a single equipment consists of four or more receptacles on it , the minimum load calculated shall not be less than 90 volt-ampere for each.

Total calculated load = 5 * 90 = 450 Volt-Ampere.

Refer:   NEC Table 220.12

The Minim general lighting load per sq.ft in dwelling unit = 3 volt-ampere

Total lighting load = 1200 * 3 = 3600 volt-ampere

General lighting load ampere rating at 120 volts = 3600/120 = 30 ampere
The minimum number of 15- ampere branch circuits required = 30/12 = 2.5 = 3

Refer :  NEC 220.52 (B)

Refer: NEC 220 .61