2017年11月10日 · \$\begingroup\$ In this case, you have the resistor in series with another load, not by itself across the power supply. An LED is a non-linear device that does not have a constant resistance. Instead, it has a (relatively) fixed voltage drop, …

If you have a resistor in a circuit, with a current flowing through it, there will be a voltage dropped across the resistor (as given by Ohm's law). If the resistor is in series with some other element, and they together are powered by a constant voltage source, then the voltage dropped across the resistor means there's less voltage available ...

2016年4月20日 · Figure 1. Simple circuit with multiple ammeters and voltmeters. Figure 2. The same circuit with the resistor and LED positions swapped. In Figure 1 we have a simple 12 V battery powering an LED. The LED needs about 10 mA to light brightly and at that current will have nearly 2 V across it. That means we need a resistor to drop the other 10 V.

2014年7月5日 · The top resistor is very difficult to know what side band is the tolerance. The only great tip for 5 bands resistors, is that Black, Orange, Yellow and White are not tolerance, so in case of all bands being spaced equally and one of those colors being at the side band, it is the first digit of the value.

2013年3月21日 · Say I have a simple circuit with a 6v supply, an 1K resistor and an LED. If I wire the resistor to the positive source, then wire that to the anode of the LED and back to ground, the circuit works fine.

This resistor performs two functions. 1) It is a pull-down resistor. 2) It is part of a voltage divider. This allows the threshold voltage to be set to the desired value. For example, it is possible to pick resistor values such that the transistor doesn't turn on until say, 120 Volts is …

2016年8月23日 · First question: Does that mean that the actual voltage of: Point A: 5V Point B: 1.73V Point C: 0V? So I am not sure if my calculations of voltage are correct. I also have this other questions: Does the resistor have to be before the component I …

2024年1月4日 · Q3: what exactly does a resistor do with the energy it is removing from the circuit? The purpose of the resistor is to set the LED current. The lower the resistor value, the higher the current in both itself and the LED, thus the more power is used, again in both.

2022年1月22日 · I do not understand how this circuit operates. As I know, for the current to flow through a circuit it should form a closed loop but I do not understand how this circuit forms a closed loop. In general, I got confused when I see a ground in the circuit. I do not know what the concepts that I am missing regarding ground connections.

By Ohm's law, the voltage across a resistor is proportional to the current thru it and its resistance. Expressed in common units: V = A Ω. where V is the voltage across the resistor, A the current thru it in Amps, and Ω the resistance in Ohms. This is …