That seems complicated, ask Google!

AP1 wrote That seems complicated, ask Google!

I'll try its easier to have it explained then have the chance to question the answer as of why.

DynamicBomb wrote

AP1 wrote That seems complicated, ask Google!

I'll try its easier to have it explained then have the chance to question the answer as of why.

Sorry I couldn't help man!

1. R=V/I is just a law of physics that says the resistance through a component is equal to the potential difference over said component divided by the current through it given certain conditions, this is Ohms law. This doesn't tell you what the appropriate resistance you need as this depends very much on what you want the resistor to act as, you need to be more specific.

2. Wirewound resistors as the name suggests use a high resistivity (another property but don't worry about it) wound inside the resistor to provide resistance in a circuit.

3. Watt is the SI unit for power. 1 watt is 1 Joule (energy) per second. You can use the formula P=I*V. Watt is just how you measure power. (Energy dissipated per unit time over a component)

4. Since power=current*potential difference (voltage) then current=power/potential difference, therefore changing the potential difference (voltage) will alter the current through the circuit.

Just what I can remember from my physics A-level, so I may not be 100% correct on everything. Hope I helped though.

TSNYC wrote 1. R=V/I is just a law of physics that says the resistance through a component is equal to the potential difference over said component divided by the current through it given certain conditions, this is Ohms law. This doesn't tell you what the appropriate resistance you need as this depends very much on what you want the resistor to act as, you need to be more specific.

2. Wirewound resistors as the name suggests use a high resistivity (another property but don't worry about it) wound inside the resistor to provide resistance in a circuit.

3. Watt is the SI unit for power. 1 watt is 1 Joule (energy) per second. You can use the formula P=I*V. Watt is just how you measure power. (Energy dissipated per unit time over a component)

4. Since power=current*potential difference (voltage) then current=power/potential difference, therefore changing the potential difference (voltage) will alter the current through the circuit.

Just what I can remember from my physics A-level, so I may not be 100% correct on everything. Hope I helped though.

1. Oh right i get it. How would i decide what resistor to use? I want a 12v fan down to about 8v, Should i get a variable resistor? Or just test a few with volt meters and see what i get?

2. Ok so its basically a different resistor but does the same job. Are these good to use? I noticed they have a much lower resistance than normal resistors and cost double the price. Are they more accurate?

3. I understand.

4. I haven't heard of that formula before but will come in handy, thanks. I'm taking it power would be volts?



this was an excellent reply +REP for you!
Was it hard getting a A-Level in physics?

DynamicBomb wrote

TSNYC wrote 1. R=V/I is just a law of physics that says the resistance through a component is equal to the potential difference over said component divided by the current through it given certain conditions, this is Ohms law. This doesn't tell you what the appropriate resistance you need as this depends very much on what you want the resistor to act as, you need to be more specific.

2. Wirewound resistors as the name suggests use a high resistivity (another property but don't worry about it) wound inside the resistor to provide resistance in a circuit.

3. Watt is the SI unit for power. 1 watt is 1 Joule (energy) per second. You can use the formula P=I*V. Watt is just how you measure power. (Energy dissipated per unit time over a component)

4. Since power=current*potential difference (voltage) then current=power/potential difference, therefore changing the potential difference (voltage) will alter the current through the circuit.

Just what I can remember from my physics A-level, so I may not be 100% correct on everything. Hope I helped though.

1. Oh right i get it. How would i decide what resistor to use? I want a 12v fan down to about 8v, Should i get a variable resistor? Or just test a few with volt meters and see what i get?

2. Ok so its basically a different resistor but does the same job. Are these good to use? I noticed they have a much lower resistance than normal resistors and cost double the price. Are they more accurate?

3. I understand.

4. I haven't heard of that formula before but will come in handy, thanks. I'm taking it power would be volts?



this was an excellent reply +REP for you!
Was it hard getting a A-Level in physics?

1. You could get a variable and alter it whilst checking the with the voltmeter to get the required results.

2. I don't know of any difference in function to be honest as I don't have much experience using them, (I'm sure they are preferable in certain conditions but I'm not sure. Google it if you want to know I'm sure there is lots of info out there). The tolerance is determined by the colour of the 4th strip on the resistor gold=+-5% of the original value and silver is +-10%.

4. There are lots of forumlas involving power, potential difference (voltage), resistance etc. Power is measured in watts (or joules per second (same thing)) although you will see watts more often as it's more conventional.

Physics A-level wasn't too bad.

by the way I'm no expert and I've certainly forgot a lot of the stuff I knew about electronics as I haven't done any in a while. There are other places you can ask where the people are a lot more experienced if you need further help.