Power Measurement Fundamentals 13
Table 1-6 lists some of the powers of 10. In a whole-number power of
10 , the power to which 10 is raised is positive and equals the number of
zeros following the 1. In decimals, the power of 10 is negative and equals
the number of places the decimal point is moved to the left of the 1.Table 1-6. Power of 10
———————————————————————
Number Power of 10
———————————————————————
1,000,000 106
100,000 105
Whole 10,000 104
numbers 1000 103
100 102
10 101
1.0 100
0.1 10 –1
0.01 10 –2
0.001 10 –3
Decimals 0.0001 10 –4
0.00001 10 –5
0.000001 10 –6
———————————————————————Scientific notation simplifies multiplying and dividing large numbers or
small decimals. For example:4800 × 0.000045 × 800 × 0.0058
= (4.8 × 103 ) × (4.5 × 10 –5) × (8 × 102 ) × 5.8 × (10–3)
= (4.8 × 4.5 × 8 × 5.8) ́ (103–5+2–3)
= 1002.24 × 10 –3
= 1.00224
= 9.5 × 104
8
= 1.1875 × 108
= 118,750,000Other Electrical Power Units
Table 1-7 shows some common units used in the study of electrical
power systems. These units will be introduced as they are utilized. You
should review this figure and the sample problems included in Appen-
dix A.