A message from our CEO about the future of Stack Overflow and Stack Exchange. Read now.

Questions tagged [resistance]

A measure of how much a conductor opposes current flowing through it. It can also refer to a part of a circuit, which has a non-negligible resistance value.

Filter by
Sorted by
Tagged with
0
votes
0answers
18 views

Equations for voltage/current through a transistor

Given the following circuit: I can figure out the current through the 'bottom wire' by doing: ...
1
vote
3answers
39 views

Is there a difference between measuring the resistance using a multimeter ohm function and using the voltage / current relation?

I need to measure the electrical resistivity of a concrete sample following the procedure described in ASTM C-1760. The procedure requires a 60V DC potential to be applied across the concrete sample ...
0
votes
1answer
66 views

How to set output resistance of an amplifier to be 50k

I need to build an amplifier using BJTs / resistors / capacitors. It should have specific parameters (up to 5% error), and I’ve reached them all except for the output resistance. The parameters are ...
0
votes
1answer
44 views

Help regarding Ac current limiting using resistor

I've 12v(Vrms) 1A AC transformer. I need to regulate it to 1to 4ma maximum output without having much voltage drop. Output load is an animal skin which has resistance in it. Can I just use a ...
1
vote
0answers
64 views

What is the total resistance in this circuit?

simulate this circuit – Schematic created using CircuitLab The parallel bit is easy enough but that 150k ohm keeps bending me over. If you could tell me how you got the answer it would help my ...
3
votes
1answer
198 views

Is volume controlled through a potentiometer?

Eletronics newbie here. I am building my first prototype (using an Arduino) that includes a volume knob. I want to know if volume is controlled by a potentiometer because I saw this video and it got ...
0
votes
2answers
39 views

BT136 inner resistance

I found two datasheets for the BT136 triac: Datasheet one Datasheet two But those datasheets didn't mention the inner resistance of the triac (or I couldn't find it.) What's the resistance ...
0
votes
2answers
96 views

Is the voltage divider in this circuit backwards for what I'm attempting to achieve?

This circuit is from another post (from long ago) where a user helped me build a circuit which would use a BJT as a switch. simulate this circuit – Schematic created using CircuitLab The ...
-1
votes
1answer
49 views

Short and Open Circuit Calculation

Suppose there is a ideal voltage source which can provide infinite power if that is needed in an ideal scenario. Now suppose a resister R is connected across it and the e.m.f is E. So by ohm's law the ...
0
votes
0answers
40 views

Why does my instrument gauge not work after splicing the wires?

I have spliced my motorcycle wiring harness that leads to the instrument gauge to extend the length. Now only the neutral indicator light works. I soldered and matched each color. Only thing I know is ...
0
votes
2answers
55 views

Finding voltages in a linear circuit

A linear circuit is shown in the figure. The elements in this circuit have the following values: R = 100 Ohms, R2 = 200 Ohms, R3 = 350 Ohms, V = 5V, and I = 0.004 A. Determine the potentials of ...
0
votes
2answers
53 views

Finding the Thevenin equivalent Resistance for circuit with voltage-dependent sources

A linear circuit containing two voltage dependent sources, as shown. The elements in this circuit have the following values: \$R_1 = 7.2k\$ Ohms, \$R_2 = 12k\$ Ohms, \$R_3 = 3.3k\$ Ohms, \$\alpha = 0....
0
votes
0answers
43 views

Why does a circuit with only reactive components have infinite Q factor?

So I came across the statement in my textbook. So I have been trying to understand why this is the case, however I just have not been able to understand
0
votes
3answers
38 views

voltage across low resistance and short circuit

simulate this circuit – Schematic created using CircuitLab The voltage across R ohm should be always V volts for every single value of R except R=0 and at that resistance the current through R ...
-2
votes
1answer
118 views

How can a wire have 0 conductivity and 0 resistance?

First post but lurking for over a year I bought some cheap heating pads on EBay a long time ago. 4v wouldn't get all 5 in parallel hot enough and 8v was unbearably hot so they went in the pile of ...
1
vote
2answers
57 views

trying to get motor to turn on

i'm very new to electronics and working thru an udemy course on an introduction to electronics. I'm trying to get this air pump to activate in a simple DC circuit on a breadboard. https://www.ebay....
0
votes
1answer
42 views

Multimeter is showing wrong resistance [closed]

I accidentally pluged my multimeter in a 220 v 50hz power supply keeping the knob on the resistance section. Now when I rotate the knob to the resistance part it always shows 24 ohms although there is ...
0
votes
1answer
50 views

How to properly wire a 4.5V LED strip with 12V motors

I'm modding a Nerf gun (Rapidstrike to be exact), and I put a 3S Lipo in there with 1000 mAh. The circuit right now is a rev switch, trigger switch, switch behind the pusher, battery, pusher motors, ...
0
votes
3answers
76 views

Why does inc R of a RL circuit increase dVL/dt. Here I have circuits and details

Why does increasing R of a RL circuit increase the rate of change of voltage across an inductor with respect to time dVL/dt. Here a 50V 2k circuit and a 5V 200ohm circuit both create a change of ...
-1
votes
2answers
66 views

Turning off and Flickering of LEDs for some reason

I've been following Ben Eater's You Tube series on building an 8 bit computer. As I built and connected more modules to the same power source, the LEDs connected to the registers started to flicker ...
0
votes
1answer
56 views

Is heating the nichrome wire with phone battery possible?

I want an nichrome wire to heat instantly red hot when connected with phone battery using 2 copper wires. Do I need any extra circuit to convert the volts into current for heating? (H=I^2Rt) Would ...
1
vote
1answer
56 views

How to detect electrical leakage in water tank?

I have a 50cm x 50cm x 80cm water tank and I am heating water with two 1500 watt water heater resistances. I think they are stainless steel or chrome plated but I am not sure about it, I can't contact ...
0
votes
2answers
37 views

Relation between current voltage .Acc. to ohm's law and P=IV

Here in image increase in current increase the voltage and vice versa Here in image when voltage increase current low and vice versa 2 pages of same books what is right and how to understand ?
1
vote
3answers
53 views

Relation between current, resistance and voltage according to Ohm's law, Joules law of heat and P=IV

According to P=IV, if P is constant with increase in I (current,) then voltage has to decrease and vice a versa - which means they become inversely proportional but according to Ohm's law they are ...
0
votes
1answer
51 views

Question about purely resistive incandescent lamps put in series and fed double normal voltage

I am curious about how and why if you take 2 purely resistive incandescent lamps (light bulbs) that are rated at 40 watts and 60 watts, both 120V AC (RMS) ratings, if you put them in series and feed ...
7
votes
3answers
2k views

Understanding capacitance in oscilloscope probe tip

I am trying to understand the capacitance and resistance in oscilloscope probe tip. In the above attached image, that 9Mohm resistance is used for that 1x and 10x setting that divides the input ...
0
votes
2answers
102 views

Is it ever a good idea to rely on wire resistance instead of a proper resistor?

I implemented a breadboard prototype based on the circuit below (image created by a LED circuit calculator here). The LEDs are SFH4556P. Voltage for the breadboard is provided by a wall wart adapter (...
0
votes
2answers
65 views

Confused about equivalent resistance

I know resistors in series have the same current, and resistors in parallel have the same voltage drop, but in practice, I can't get the equivalent resistance right. Wondering if anyone has tips/...
-1
votes
2answers
55 views

How to know if the load is variable one? [closed]

For example, I have an air conditioner. How to know if such a device has a variable load or not ? NOTE: Air conditioner is just an example. My question is in general how to know ?
0
votes
1answer
40 views

Advice on a voltage measuring circuit

I've been working on a voltage divider circuit that will hopefully allow me to measure voltages between 0-60 kV DC (80 W) as 0-889 volts DC. The voltage divider section that is used to measure the ...
1
vote
1answer
44 views

Switching depending on resistance from fuel gauge sender unit [closed]

I hope someone can offer a solution to the following situation: We currently have a fuel gauge operating at between 12,6 and 14,6 VDC. The sender unit ranges from 10 ohms (empty) to 300 ohms (full). ...
0
votes
1answer
39 views

Effective impedance calculation for noise removal from supply

I am working on single supply Op-Amp amplifier, referring to this post. While calculating the value of the capacitor C2, as to pass all the noise from the supply to the ground. I am unable to ...
0
votes
1answer
37 views

What component can I use to control the brightness of an LED strip?

I know that to adjust the brightness of a single LED, I can control the current using a resistor. What about for a strip of LEDs being fed by a 24V 1.8A power supply? I'd assume that the power being ...
2
votes
2answers
37 views

Switched capacitor resistor

I have some basic doubts about switched capacitor resistors: With this circuit we get an equivalent resistance equal to (Reference: Wikipedia): Where f is the frequency of the clock signals that ...
0
votes
2answers
68 views

Amperage limiter?

I'm looking for a component that essentially limits the current passing through it, but unlike a resistor, its resistance is not constant. When the current passing through this component is below the ...
0
votes
2answers
59 views

Increase resistance to turn on a light bulb

I’m wondering if it is possible to use a potentiometer to turn on/off a lightbulb in a binary manner. I’m thinking high resistance = light on. Low resistance = light off. Is there such a circuit? ...
0
votes
1answer
26 views

Trouble understanding thevenin's model from AoE Lab

I am using the AoE lab book to teach myself electronics. I am on the voltage divider section, and I am confused at their simplified explanation. I'd like to explain it a different way, but I am not ...
0
votes
1answer
33 views

What is the difference between transresistance and differential resistance?

Transresistance is defined as the change in output voltage over change in input current. While differential resistance is defined in the same manner. So what is the difference ?
0
votes
1answer
41 views

Calculating resistance for integrated circuit with logical gates, so that the circuit works properly

I have found this task with its solution: For the circuit shown below calculate \$R\$ so that the circuit works properly. All gates belong to the \$TTL\$ series. Solution: $$\begin{...
0
votes
1answer
50 views

How to find equivalent resistence of this mixed circuit?

Find equivalent resistance, the current in R5, Voltage of R2 and power of R10. Actually, I don't know if my attempt is right. So, you would point out where there are mistakes, pleased. R10 and R11 ...
0
votes
1answer
44 views

Measuring Voltage drop across MOSFET 2N7000

My setup is 2.1V on the gate. A 330 Ohm load between Vdd and drain. And Source to ground. I stepped Vdd from 0V to 9V in small increments and measured the current through Vdd to ground. Got currents ...
-1
votes
1answer
73 views

Fraction resistance and negative resistance

Is it possible that the resistance will be fraction or negative number and what's happened?
1
vote
2answers
177 views

Can a resistance be negative?

I have to calculate the value of a resistor so that my circuit has a certain equivalent resistance. This is the circuit, and here are the values: ...
0
votes
3answers
57 views

Finding R equivalent

simulate this circuit – Schematic created using CircuitLab When finding Req between M and N i can't understand why current isn't flowing in R3 and R4.
0
votes
3answers
77 views

Current and resistance

Can anybody explain why my tongue gets a reading on a multimeter. Do I have a current? Why do i have resistance? Why do some things have resistance? I am very confused.
0
votes
0answers
51 views

How does an e-cigarette dry tank protection sensor work?

E-cigarettes work with a resistance coil which heats liquid into vapor. Some e-cigs have a dry-tank protection, which senses when the coil does not have any liquid to heat, to avoid it getting too hot....
0
votes
1answer
27 views

Ground with one sensor vs multiple sensors

I'm pretty new to the world of electronics and was working on an Arduino project using load cells and HX711 amplifiers. The project consists of four HX711 connected to the Arduino and Pi, with all ...
-1
votes
1answer
73 views

Circuit solving problem

I am a high school boy and came across this question: I have solved this question by KVL, but how do I solve this question by potential distribution method? What I have tried :) I assume two ...
0
votes
1answer
37 views

Finding Equivalent Resistance - does order matter?

Conceptual question: When you have a super complicated circuit, does it matter which node you start at when finding equivalent resistance? How about capacitance?
1
vote
1answer
72 views

Is power balance a relevant factor in the consumption of a house?

Where I live, houses receive up to three phases from the electricity provider. There is a company advertising a power balancing service. They claim that if one of the three phase cables is overloaded,...