The answers here are presented in bold.


Some notes:

  1. Ordinary Number and Engineering Notation are subjective. For example capacitance (farad, F) is more often written in pF, or µF, even when other prefixes could be used. For example, 4700 µF is used more often than 4.7 mF, and capacitances between 1 nF and 1 µF are often given in pF or µF e.g. 0.047 µF instead of 47 nF, or 1200 pF (or 0.0012 µF) instead of 1.2 nF.

Question 1

Express the following in appropriate Engineering Notation (in '× 10 to the power of ± 3' format ).

NOTE:

  1. It is assumed that "appropriate Engineering Notation" means that the significand is in the range 1 to 999.9….

Quantity
 Engineering
Notation
 Comment
45,000,000 Wh
 45 × 106 Wh
 Example, already filled in. Shift the decimal point six places to the left (45000000 → 45000 → 45), then multiply by 106 to compensate.
0.025 6 A 25.6 × 10-3 A Shift the decimal point three places to the right (0.0256 → 0.256 → 2.56 → 25.6), then multiply by 10-3 to compensate.
65,000 J
 65 × 103 J Shift the decimal point three places to the left, then multiply by 103 to compensate.
27,200 V
 27.2 × 103 V
 Same as for the 65,000 J example.
0.000 05 A
 50 × 10-6 A Shift the decimal point six places to the right (0.00005 → 0.05 → 0.5 → 5 → 50), then multiply by 10-6 to compensate. The '5' at the end of the Initial Quantity needs a trailing zero added to make its first 3-digit group that has a non-zero digit 3 digits long i.e. 0.000 05 → 0.000 050.
2000 V
 2 × 103 V
45,340,000,000 J
 45.34 × 109 J
0.000 000 005 78 F
 5.78 × 10-9 F


Question 2

Complete the following table, use appropriate values:

NOTES:

  1. The term "appropriate value" is subjective. An appropriate value for Engineering Notation can be considered any significand from 0.001 to 999.9….
  2. The term "Ordinary Notation" has no strictly defined meaning. If no unit is specified, it is recommended to keep the significand in the range 0.001 to 999.9….
  3. The significand on the Multiple/Submultiple is being kept in the range of 0.001 to 999.9….
  4. Units in italics in the "Ordinary Notation" are units that have been selected where no unit was already given.
Ordinary Notation
 Multiple /
Submultiple
 Engineering Notation
 Comment
25,000 V 25 kV
 25 × 103 V
 Example, already filled in.
0.003 54 Ω
 3.54 mΩ  3.54 × 10-3 Ω
0.027 A 27 mA  27 × 10-3 A
500 µC 500 µC 500 × 10-6 C No unit is given for the "Ordinary Notation". However, the Multiple/Submultiple appears sufficiently clear, so it has been used unmodified.
0.015 µF 15 nF 15 × 10-9 F The Engineering Notation form "0.015 × 10-6 F" may also be deemed acceptable, depending on context.
0.0872 GWh 87.2 MWh 87.2 × 106 Wh
4,500 A 4.5 kA 4.5 × 103 A
0.005 mA 5 µA 5 × 10-6 A
0.000256 mH 256 nH 256 × 10-9 H 1 nH = 10-6 mH
0.00814 nF 8.14 pF 8.14 × 10-12 F 0.00814 nF = 0.00814 × 10-9 F = 0.00814 × 103 × 10-12 F = 8.14 × 10-12 F
25,870 VA 25.87 kVA 25.87 × 103 VA
7,5000,000 J 7.5 MJ 7.5 × 106 J
56,230 V 56.23 kV 56.23 × 103 V
0.056 mF 56 µF 56 × 10-6 F


Last modified: Tuesday, 12 May 2020, 3:09 PM