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It is a general description of what we showed in the last video of the unit (and you did the calculation for Question 11).
Potential energy is another term for voltage. See Unit 1
You can solve this with one of the Ohm’s Law equations from the pie chart in Unit 3.
First, let’s think about what is being described. A heating element is going to be used in a 240vac circuit and is designed to produce about 5600 watts of heat.
In other words, the resistance of that heating element will be the right value so that the current in the circuit that goes through it will generate the right amount of heat given a voltage of 240v.
We can calculate what the resistance would be.
When you are asked to calculate something, always clearly identify two things:
1. What are you being asked to find?
2. What information are you given?
In this case:
1. Resistance (R, in ohms)
2. Power (P, 5600 watts), and voltage supply (E, 240vac)
So, look at the Ohm’s Law pie chart. Can you see which formula would be appropriate to use?
Rewatch the video in Unit 1 from about the 15 minute mark through 20:30.
The single-phase magnetic field ________ whereas the three-phase magnetic field _______ _________ the stator.
Ah, that was an old Amazon link that is no longer valid.
You can search “anti static wrist strap” at Amazon. Here’s their “bestseller”
The Quiz and Exam reset request form is under “Contact” in the main menu.
Here’s the direct link:
Eddon, please post your replies in the thread that you are referring to, and be sure you are in the correct forum. You are currently taking the Fundamentals course, so your posts should be in the Forum for the Fundamentals course.
You don’t need a reset.
Did you see my reply to your post about Question 8?
If you can arrive at the correct answers for that question, then I’ll be able to give you enough points to pass the exam. Please reply to my questions there in that post.
Let’s see if we can help you figure out the correct answers on Question 8.
Here’s what you have correct so far:
Ignitor – 120vac
Safety – 120vac
The booster and the main coil are NOT 60vac each.
Tell me this: if you do the “Zen trick” on the ignitor, how do you reach N?
Then tell me the same thing for the Booster.
It sounds like you’ve got it!
In that second step (power), make sure you just use the resistance of the loose connection, since that’s what we’re asking for. Some students accidentally use the total resistance there, which gives the heat generated by both loads together.
Yes, the increased total resistance (due to the loose connection) decreases the current, because that’s the relationship of E, I, and R.
(Voltage supply is set at 240v and won’t change.)
And because power/heat and current are directly proportional, that means the heat generated by the element will decrease from what it would be if there was no loose connection adding extra resistance and thus decreasing the current.
Let me know if you have any other questions.
- This reply was modified 1 month ago by Susan Brown.
The two questions that you missed are both based on the video at the end of Unit 3, on the heat generated by the loose connection.
Have you rewatched that video, writing down the calculations for yourself?
There are basically two steps.
1. Find the circuit current. (Remembering that the current will be the same throughout the circuit, and is determined by the total resistance in the circuit.)
2. Find the heat generated by the loose connection, using the circuit current and the resistance of that loose connection.
The electrons that are moving between the ignitor or booster to/from N have a choice, correct? They can go through the Main coil, or they can go through the closed detector switch.
If you were an electron, which route would you choose?
Happy to help!
First step – do the “Zen trick” on the ignitor. How do you reach N?
Second step – do the same thing on the booster – How do you reach N?
A cam is a very simple mechanical device that you find in many different applications, from sewing machines to car engines to timer motors. All it is is an oval-shaped disc attached to a shaft. If the shaft rotates so that the long part of the oval is facing an actuator, the actuator will get pushed down. In the case of a timer motor in an appliance, this actuator would be a switch contact.
This demonstrates their action pretty well:
It basically opens and closes switches.
You don’t need to know all of these details for now- you won’t be quizzed on timing charts. We just want you to get introduced to them.
Hi Joe – I already answered this question (note – I had to move the topic to the correct Forum – the one for the Fundamentals course)