Arithmetic of magnetism and electricity by Morrow John Thomas

Author:Morrow, John Thomas. [from old catalog] & Reid, Thorburn, [from old catalog] joint author
Language: eng
Format: epub
Tags: Electricity
Publisher: Lynn, Mass., Bubier publishing co.
Published: 1893-03-25T05:00:00+00:00

length across the wires is great compared with its depth, 80 may be taken as a fairly conservative value for this constant, which means that for every watt per square inch of radiating surface, the temperature will rise 80° centigrade. By the radiating surface is meant the. surface of the wires themselves. The ends of the coil are not taken into account.

Example 1.

A field coil has a resistance of 1 ohm, and a current of 12 amperes flows through it.

It is 12 inches long and the diameter of its radiating surface is 12 inches. How much will it rise in temperature?

Solution:

Watts = 12 2 X 1 = 144.

Radiating surface = 12 X 3,142 X12—452.

Watts per square inch = \^\ =:.319.

Rise of temperature in degrees centigrade = 80 X.32 = 25.6.

Example 2.

A field coil has 6,000 ampere-turns, 450 turns, resistance .47 ohms, length across wires 8^ inches, diameter of surface 12 inches. Find the watts per square inch and the probable rise in temperature.

Solution:

Current = 6 -^ 0 / = 13 i-

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.