Envelope Sizes

DL, 220 x 110 mm, A4 folded to third of original size
C4, 229 x 324 mm, A4, A3 folded in half
C5, 162 x 229 mm, A5, A4 folded in half
C6, 114 x 162 mm, A6, A5 folded in half, A4 folded in quarter
10, 241 x 105 mm, 1/3 of letter paper, 1/4 of legal paper

Bits Per Second

The following are common data rates used in serial communications such as RS232/RS485:
60, 75, 110, 150, 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
Some of the original PCs used a 8250 UART (universal asynchronous receiver/transmitter) IC along with a 1.8432MHz crystal which was divided down:
1.8432MHz divided by 16 equals 115200
1.8432MHz divided by 48 equals 38400
1.8432MHz divided by 192 equals 9600

Wire Gauges

12 AWG, area 3.31 mm2, 14 amps
16 AWG, area 1.31 mm2, 7 amps, 19/0.3
18 AWG, area 0.823 mm2, 5 amps, 24/0.2
22 AWG, area 0.326 mm2, 2 amps, 7/0.25
24 AWG, area 0.205 mm2, 1.5 amps, 7/0.2
30 AWG, area 0.051 mm2, 0.3 amps, 7/0.1
The above current carrying figures are very approximate, and are based on a copper 7 to 24 strand wire. Please always check with the wire manufacturers technical specifications.
7/0.2 wire consists of 7 strands of 0.2 mm diameter wire, total area 0.22 mm2, close to 24 AWG.

dBm / Watts / Voltage

Below is a table comparing dBm to Watts and the voltage into a 50 Ohm load:

Paper Sizes

A0, 33.1 x 46.8 inches, 841 x 1189 mm
A1, 23.4 x 33.1 inches, 594 x 841 mm
A2, 16.5 x 23.4 inches, 420 x 594 mm
A3, 11.7 x 16.5 inches, 297 x 420 mm
A4, 8.3 x 11.7 inches, 210 x 297 mm
A5, 5.8 x 8.3 inches, 148 x 210 mm
Note that A5 is half the area of A4, A4 is half the area of A3 etc.
Half Letter, 5.5 x 8.5 inches, 140 x 216 mm
Letter (A), 8.5 x 11 inches, 216 x 279 mm
Legal, 8.5 x 14 inches, 216 x 356 mm
Junior Legal, 5 x 8 inches, 127 x 203 mm
Ledger / Tabloid (B), 11 x 17 inches, 279 x 432 mm
C, 17 x 22 inches, 432 x 559 mm
D, 22 x 34 inches, 559 x 864 mm
E, 34 x 44 inches, 864 x 1118 mm

Ethernet Address Ranges

Below is a table showing Ethernet address ranges inlcuding the netmask and number of devices: