Comments: Voltage, Current, Resistance, and Ohm's Law


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  • Member #506941 / about 3 years ago / 1

    To start with this is a graet blog on this topic. It is almost 90% perfect. With that said, It would help if Sparkfun followed WCAG Web Accessibility guidelines when writing blogs. I know this is an older blog but WCAG has been out for that long at least. The alt text on this page are not helpful for peoples with disabilities. There are many blind and Low Vision people who work in electronics. In fact the Cruise control was created by a blind engineer just to name one. With that said. It would be nice if the alt tags on this page were filled in with useful information rather than the default "alt tag" Useful information would be text forms of equations and descriptions of diagrams. See the W3C Web accessibility guidelines and especially pay attention to 1.1.1 on describing none text elements. There are lots of up and coming Blind makers and it would be good if your learning Blogs were accessible.

  • Member #1276465 / about 6 years ago / 1

    In the example with the tanks of the same amount of water except one has a larger pipe and the other has a smaller pipe, it says the voltage is the same in both both the amperage is lower in the one with the smaller pipe. Since current is the amount of electricity that flows past a given point in any given time, wouldn't they both have the same current? Because although the smaller pipe would restrict the dimensions of water, wouldn't the speed of the water in the smaller pipe increase which would in turn lead to its current being the same as the larger pipe?

  • Member #1274430 / about 6 years ago / 1

    "“1 Ohm” as the resistance between two points in a conductor where the application of 1 volt will push 1 ampere, or 6.241×1018 electrons." -- looks like this sentence has "per second" missing from the end.

  • Member #1011936 / about 7 years ago / 1

    At the beginning of text you said "The pressure at the end of the hose can represent voltage" . but in the ohm law section you said "The amount of water in the tank is defined as 1 volt ". There is a difference between the two sentences. Please explaining more. thank you.

  • Member #802147 / about 8 years ago / 1

    "We’ve chosen a resistor value that is high enough to keep the current through the LED below its maximum rating, but low enough that the current is sufficient to keep the LED nice and bright."

    I think you need to reverse "high" and "low" there. It's low enough that it won't exceed the LED's rating; it's high enough to keep the LED bright.

    • Member #977687 / about 7 years ago / 1

      Nope - the references (high and low) are in the correct positions. If the statement was, “We’ve chosen a CURRENT value..." THEN you would need to swap them out. The current needs to be below the current rating - higher resistance means lower current, and lower resistance means higher current.

  • Kyle1988 / about 8 years ago / 1

    At first it says voltage is a difference in charge between two points. If it's a difference in charge, why can't it be measured in coulombs?

  • very good for me !!

  • Member #649069 / about 9 years ago / 1

    Very interesting and much useful. Thank u... So much.

  • Member #502085 / about 10 years ago / 1

    I suggest you guys make series of tutorial videos in the education channels for youngsters, and put them up on MOOC channels.

  • Member #487358 / about 11 years ago / 1

    Thank you for the explanation. Very easy to understand.

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