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Resistance: Electrical resistance describes how an electrical conductor (a wire) opposes the flow of an electrical current (flow of electrons). To overcome this opposition a voltage (a energy) must dropped (used) across the conductor (wire). Resistance can be described by ohms law: Ohms Law: R = V / I (Resistance = Voltage / Current) (resistance measured in ohms) where: Voltage [V]= the energy lost across an component (voltage measured in volts). Current [I] = the charge (electrons) flowing through an component (current measured in Amps). Electrical resistance can be thought of as sticking your hand out a car window. The faster [current] you drive the harder the wind presses [resistance] against you hand and therefore it takes more energy [voltage] to hold your steady. When trying to overcome electrical resistance, the electrical energy lost is turned into heat. This is how the elements of a household stove, toaster, and fan heater work. Because of the vacuum in a light bulb, the electrical energy lost is instead turned into light. It can be seen the electrical resistance plays a large role in modern life. Resistor: The resistor is the most common electronic component and is used to limit and/or control the voltage and current in an electronic circuit. Resistors are carefully manufactured to provide a predetermined value of electrical resistance which may range from 0.1 ohms to 100,000,000 ohms, depending on the application. The physical size of a resistor also varies dependant on the amount of power passing through the resistor, given by: P = V x I (Power = Voltage x Current) (power measured in watts) There are also many types of resistors including: · Variable Resistor - changes resistance when its shaft is rotated (volume knob on a stereo). · Thermistor - changes resistance when the temperature changes (used in a thermostat). · Light Dependant Resistor (LDR) - changes resistance when the lighting changes (used in children's night-lights). Resistor Example: An LED is a small red light (such as the one on the front of most TVs) and requires 2.0 volts and 0.02 amps to operate correctly. If we connected that LED up directly to a 12 volt battery, the voltage would be too high, and too much current would flow… the LED would blow up. We need to use a resistor to limit the voltage and current. But which value of resistance should the have resistor? Uses ohms law: R = V / I = (12.0 - 2.0) / 0.02 = 500 ohms (Note: the voltage across the resistor is the battery voltage minus the voltage we want across the LED) But which value of power should the resistor be capable of handling? P = V x I = (12.0 - 2.0) / 0.02 = 0.2 Watts hope this helps
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Can you use a 91ohm resistor in place of 100ohm resistor?
It depends on where you are going to use this resistor and what its application going to be. If the circuit you are using can tolerate this then you are fine.
What resistor should you use to get 9v to 6v?
You can only use a resistor to drop a voltage at a constant current. If you know the current, use Ohm's law to calculate the resistor value.
How do you use resistor in a sentence?
I installed a resistor inline with my oil pressure sensor. The resistor in a circuit will usually disperse energy as heat.
Can you calculate the resistance of a component using a meter and a resistor?
yes you can! you can use a multimeter and a resistor.
Why you use 250 Ohm resistor in series with HART protocol communication?
You need to use the 250 Ohm resistor in series with HART protocol communication because it acts as a shunt resistor.
Do you use resistor spark plugs with resistor wire plug ends?
No, Using a resistor spark plug with resistor wires can create too much resistance for the ignition system.
What is resistor and its use and working?
resistor is a passive component which opposes the current flowing through a closed ckt. use in opposition of current in ckt .
Resistor and capacitor built circuit for alarm switch?
I wanna use resistor , capacitor and amplifier 7173 for switch alarm circuit. How can i choice resistor and capacitor value because i wanna use 24V DC.
What is the use of a photo resistor?
A night light:)
Why you use resistor with variable resistor?
Often we want to easily change a resistor value, so we use a variable resistor. For example, we may want to change the resistor that controls the power sent to a LED, so we can easily make it brighter or dimmer. Often if we use a variable resistor, there is only a very narrow range that is useful. Continuing our example, sometimes we use several LEDs, and we use the variable resistor to set them all to the same brightness. In this case, the resistance range that sets the LED to be twice as bright as the the other LEDs, and the resistance range that sends so much power to the LED that it is permanently destroyed is even less useful. So we add a fixed resistor in series with the variable resistor -- the fixed resistor sets the minimum net resistance, no matter how we turn the knob on the variable resistor. In our example, the addition of the fixed resistor allows us to turn the variable resistor throughout its whole range, and the LED gets brighter and dimmer; without that resistor, a certain range of the knob on the variable resistor would allow so much power to go to the LED that it would be destroyed.
What is the use of ceramic resistor?
there is less loss of energy through heat, ergo making a more efficient resistor.
What resistor can you use to replace a 47 kilo-ohm resitor?
You should use the same size resistor; a 47 kilo-ohm.CommentThe correct spelling is 'kilohm'.
