A disease that is of uncertain or unknown origin is referred to as:

Electrical interlocking is done exclusively by using double acting pushbuttons.

What is the operating voltage of most magnetic control systems?

When stepping the voltage down from 480 volts, the two primaries are wired in parallel to double the effective turn ratio. 

In an 8-pin relay, pins 2 and 7 are _____.

Eddy current losses are generally prevented using a solid core material.

Relays and Contactors are electronic switches.

The molar concentration of H+ ions in a solution is 5.8 × 10−9. The pH is _____ .

One Avogadro’s number of iron (Fe) atoms would weigh _____ .

How many electrons are in the outer shell of element 15?