25 Question Basic Electrical Theory Exam

[Safety Guy]

The following questions have very odd answers. The second one is flat out wrong and I give an example of a site to go to in order to prove it.

<<A holding relay is primarily used for worker convenience.>>

I think safety is the primary reason. Without holding relays it woud be extremely unsafe to operate many types of equipment. While I agree convienance is nice, that isn't the primary reason. I think honestly there is no "right" answer to this question since any answer will be an opinion.

<<The best conductors, in order of their conductivity, are: gold, silver, copper, and aluminum.>>

Ordered according to their conductivity, you have: Silver, copper, gold, aluminium, magnesium, zinc, cadmium, nickel, iron, platinum, lead, (solid) mercury, steel.
http://kr.cs.ait.ac.th/~radok/physics/k4.htm

Also includes a chart showing resistance.

 

[bphgravity]

Check your e-mail. Mike Holt sent out a notice indicating the exam has been corrected from a scoring glitch...

 

[don_resqcapt19]

Bryan,
I retook the test last night after the e-mail and there are still wrong answers there. I also agree with safety guy that there a large number of reasons to use a holding or seal-in contact in a control circuit. That is very poor question.
Don

 

[hillbilly]

Where are the questions?
steve

 

[finhead]

I'm sure we can all come up with good reasons to use a holding relay; low voltage release, and the inability of the motor to restart automatically after an interruption in service would be my contribution.
However, convenience to the worker or operator is not even close.