# Questions tagged [ohms-law]

A well known relationship that describes the relationship between Voltage and current through a device's resistance expressed mathematically as V= IR. This formula says that voltage across the device is equal to the current through the device multiplied by the resistance.

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61 views

### Creating a small range, small baseline varying resistor

I am doing a design project on making a passive varying resistor device. I have a flex sensor that increases in resistance when you bend it. It has a 10k ohm nominal resistance and increase to 110k ...
95 views

### Why would venting an engine create a negative amperage on a generator?

I'm writing simulation software for a civilian helicopter. The helicopter has two engines and two generators. Normally, we calculate the amperage reading of a generator through Ohms. I = W / V. ...
37 views

### Calculate current through a resistor attached to an ADC?

I have a resistor, R1 = 100 kΩ, connected between a: DAC PIN_1 outputting 1.34 V ADC PIN_2 At PIN_2 I measure 0.57 V. Can i model the circuit as:PIN_1 -- 100 kΩ R1 -- PIN_2 -- R_ADC -- GND? For V1 ...
53 views

### How is the current adjusted from a power bank with adjustable current?

When using a power bank with adjustable current I'm just wondering how the current is adjusted? it can't be anything to do with resistance of the recieving component because this would be constant, ...
34 views

### Battery Charger in Parallel with System Load Current Sharing - Power Path Control

Currently, I'm building a project which can either run connected over USB or via a battery. The project itself switches between either high current draw at around 450mA or low current draw at 50mA. ...
90 views

### Two of the same resistors have different resistance?

I am doing some work on the electronics of a guitar and in doing so was testing some old circuitry. I noticed that there are two resistors each stamped with ‘223’. When checking the resistance of ...
69 views

### The best way to wind copper wire around rod for lowest resistance

So I have wound 200m copper wire around a rod which gives me 180 Ω, previously I got only ~80 Ω. Both of them were randomly shuffled and the first attempt was on bigger in diameter rod. How to make ...
73 views

### Solving simple parallel/series without Req

Given the following circuit with three resistors, R1=100Ω, R2=200Ω, R3=300Ω: To solve this using the $R_{eq}$ trick: ...
86 views

### How can a light bulb run on different voltages (USA and EU)?

There is a concept in EE I don't understand. In Europe we have a 230 V supply voltage and in the USA e.g. 120 V. Now the thing I don't understand, how can I use my charger( or a light bulb) in ...
46 views

### How to calculate R for an AC load on a 3-ph system

I'm trying to calculate the resistors in an AC dummy load for a 3-ph system. A simplified schematic can be found below. The idea is to switch (with regular AC 1-ph contactors) some resistors on each ...
50 views

### How to find the current value in this circuit?

Here is the question i am getting how to proceed after finding the voltage My attempt : Next part of solution:
100 views

### Solving a circuit with node voltage method

I have the following circuit: Knowns: Iz = 80 mA R1 = 100 Ohms R2 = 150 Ohms R3 = 220 Ohms R4 = 330 Ohms R5 = 100 Ohms As I understand Gi stand for the current source internal conductivity, but ...
2k views

### How do I calculate expected output voltage of car audio amplifier with given conditions?

I have a 4-Channel Amplifier rated at 800 Watt RMS per channel @ 2 Ohm load. Channel 3 and 4 are preset to operate a subwoofer speaker while Ch 1 and 2 are set to operate mid-range speakers at ...
62 views

### Is my wire rated at a high enough current?

I am in the process of planning a speaker build. I am making sure my current wiring is up to the demands of a new system. The amplifier is a CV 1800, which can put out 9.5 amps at 4 ohms in stereo (...