1
Q
- The decimal equivalent for the fraction “1/2” is _____.
(a) 0.50
(b) 0.70
(c) 2
(d) 5
A
A
2
Q
2. The approximate decimal equivalent for the fraction “4⁄18” is \_\_\_\_\_. (a) 0.20 (b) 2.50 (c) 3.50 (d) 4.50
A
A
3
Q
- To change a percent value to a decimal or whole number, drop
the percentage sign and move the decimal point two places to
the _____.
(a) right
(b) left
(c) depends
(d) none of these
A
A
4
Q
- The decimal equivalent for “75 percent” is _____.
(a) 0.075
(b) 0.75
(c) 7.50
(d) 75
A
A
5
Q
- The decimal equivalent for “225 percent” is _____.
(a) 0.225
(b) 2.25
(c) 22.50
(d) 225
A
A
6
Q
- The decimal equivalent for “300 percent” is _____.
(a) 0.03
(b) 0.30
(c) 3
(d) 30.00
A
A
7
Q
7. The method of increasing a number by another number is done by using a \_\_\_\_\_\_. (a) percentage (b) decimal (c) fraction (d) multiplier
A
A
8
Q
- An overcurrent device (circuit breaker or fuse) must be sized no
less than 125 percent of the continuous load. If the load is 16A,
the overcurrent device will have to be sized at no less than
_____.
(a) 17A
(b) 20A
(c) 23A
(d) 30A
A
A
9
Q
- The maximum continuous load on an overcurrent device is
limited to 80 percent of the device rating. If the overcurrent
device is rated 100A, the maximum continuous load is _____.
(a) 72A
(b) 80A
(c) 90A
(d) 125A
A
A
10
Q
10. The feeder calculated load for an 8 kW load, increased by 20 percent is \_\_\_\_\_. (a) 8 kW (b) 9.60 kW (c) 10 kW (d) 12 kW
A
A
11
Q
- What’s the reciprocal of 1.25?
(a) 0.80
(b) 1.10
(c) 1.25
(d) 1.50
A
A
12
Q
- A continuous load requires an overcurrent device sized no
smaller than 125 percent of the load. What’s the maximum
continuous load permitted on a 100A overcurrent device?
(a) 75A
(b) 80A
(c) 100A
(d) 125A
A
A
13
Q
- Squaring a number means multiplying the number by itself.
(a) True
(b) False
A
A
14
Q
What’s the power consumed in watts by a 12 AWG conductor that’s 100 ft long and has a resistance (R) of 0.20 ohms, when the current (I) in the circuit is 16A? Formula: Power = I2 x R (a) 50W (b) 75W (c) 100W (d) 200W
A
A
15
Q
- What’s the approximate area in square inches of a trade size 2
raceway?
Formula: Area = π x r2, π = 3.14, r = radius (½ of diameter)
(a) 1 sq in.
(b) 2 sq in.
(c) 3 sq in.
(d) 4 sq in.
A
A
16
Q
- The numeric equivalent of 42 is _____.
(a) 2
(b) 8
(c) 16
(d) 32
A
A
17
Q
- The numeric equivalent of 122 is _____.
(a) 3.46
(b) 24
(c) 144
(d) 1,728
A
A
18
Q
- What’s the maximum distance that two 14 AWG conductors can
be run if they carry 16A and the maximum allowable voltage
drop is 10V?
D = (Cmil x Evd)/(2 x K x I)
The cmil area of 14 AWG = 4,110 cmil [Chapter 9, Table 8]
D = (4,110 Cmil x 10V)/(2 x 12.90 ohms x 16A)
(a) 50 ft
(b) 75 ft
(c) 100 ft
(d) 150 ft
A
A
19
Q
19. What’s the current in amperes of an 18 kW, 208V, three-phase load? Current: I = VA/(E x √3) Current: I = 18,000W/(208V x 1.732) (a) 25A (b) 50A (c) 100A (d) 150A
A
A
20
Q
- Deriving the square root of a number is almost the same as
squaring a number.
(a) True
(b) False
A
A
21
Q
- What’s the approximate square root of 1,000?
(a) 3
(b) 32
(c) 100
(d) 500
A
A
22
Q
- The square root of 3 is _____.
(a) 1.50
(b) 1.732
(c) 9
(d) 729
A
A
23
Q
- The volume of an enclosure is expressed in _____, and is
calculated by multiplying the length, by the width, by the depth
of the enclosure.
(a) cubic inches
(b) weight
(c) inch-pounds
(d) none of these
A
A
24
Q
- What’s the volume (in cubic inches) of a 4 x 4 x 1.50 in. box?
(a) 20 cu in.
(b) 24 cu in.
(c) 30 cu in.
(d) 33 cu in.
A
A
25
25. What’s the kW of a 75W load?
(a) 0.075 kW
(b) 0.75 kW
(c) 7.50 kW
(d) 75 kW
A
26
26. The approximate sum of 2, 7, 8, and 9 is equal to _____.
(a) 20
(b) 25
(c) 30
(d) 35
A
27
```
27. The output power of a transformer is 100W and the transformer
efficiency is 90 percent. What’s the transformer input if
the output is lower than the input?
Formula: Input = Output/Efficiency
(a) 90W
(b) 100W
(c) 110W
(d) 125W
```
A
Electrician's Math
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