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A variable resistor is very important in a circuit, because it allows you to build a circuit with some degree of control. For example, a volume knob can be a variable resistor. It can act as a control on the amount of current flowing.
This depends mostly on the circuit it is used in. Some typical purposes are:
- variable adjustment of circuit to meet users need: volume, brightness, contrast, etc. controls.
- trimmer to compensate for component tolerances in circuit.
- compensation for distortions of device driven by circuit.
- etc.
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∙ 11y ago
Wiki User
∙ 10y agoVariable resistors (often called a rheostats or potentiometers) are commonly used in light dimmer knobs and volume knobs. By turning the knob to minimize the resistance, more current flows, and the light is brighter or the volume louder. By turning the knob to maximize the resistance, less current flows, making the light more dim or the volume lower.
Wiki User
∙ 15y agoA variable resistor is most commonly used for volume controls or lighting dimmers.
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∙ 8y agoit can either reduce the current speed of electrons or increase the speed
Wiki User
∙ 11y agothe function of variable resistor is to provide variable resistances in circuitary ,
its also do the function of providing different values of current to different components....
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∙ 13y agoA: How else would your 100 watts amplifier be able to vary the sound so your neighbors don't complain about it.
Wiki User
∙ 13y agoa blower motor
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Calculate the power used in 2ohm resistor in each what circuits- 1 a 6V battery in series wid 1ohm and 2ohm resistors 2 a 4V battery in parallel wid 12ohm and 2ohm resistors?
1). 6V battery, 1-ohm resistor, 2-ohm resistor, all in series:Total resistance = 3 ohms.Current in the loop = 6/3 = 2 amperesPower dissipated by the 2-ohm resistor - I2R = 8 watts.2). 4V battery, 12-ohm resistor, 2-ohm resistor, all in parallelThe 12-ohm resistor is irrelevant.4 volts across the 2-ohm resistor.Power dissipated by the 2-ohm resistor = E2/R = 8 watts.
If a current of 2 amps flows through a 12 ohm resistor what is the voltage across the resistor?
V = (I) x (R) = 2 x 12 = 24 volts
A 120 ohm resisto a 60 ohm resistor and a 40 ohm resistor are connected in parallel to a 120 volt power source What is the current running through the 60 ohm resistor?
If they're in parallel, then each resistor acts as if it were the only one,and the presence of any others is irrelevant.The current through the 60-ohm resistor is I = E/R = (120/60) = 2 amperes.
What is JFET and VVR?
JFET as a VVR-Voltage Variable ResistorFET is a device that is usually operated in the constant-current portion of its output characteristics. But if it is operated on the region prior to pinch-off (that iswhere VDS is small, say below 100 mV[ohmic region of JFET]), it will behave as a voltage-variable resistor (WE). It is due to the fact that in this region drain-to-source resistance RDS can be controlled by varying the bias voltage VGS. In such applications the FET is also referred to as a voltage-variable resistor or volatage dependent resistor. It finds applications in many areas where this property is useful.Figure shows the drain characteristic curves for a 2N 5951 in the ohmic region (i.e. for low VDS). From the characteristic curve it can be seen that RDS varies with VGS. For example, when VGS = 0, RDS = 133 ohm and when VGS = - 2 V, RDS = 250 ohm. Because of this a JFET operating in the ohmic region with small ac signals acts as a voltage-controlled resistance.Note that the drain curves shown in figure,extend on both sides of the origin. This means that a JFET can be employed as a voltage-variable resistorfor small ac signals, typically those less than 100 mV. When it is employed in this way, it does not require a dc drain voltage from the supply. All that is required is an ac input signal.
A 10 ohm resistor has 20 volts across it. What will the current will be.?
I = E/R = 20/10 = 2 Amperes.Note: Don't try this at home.The power dissipated by a resistor is I2R = 40 watts for this one.Unless your 10-ohm resistor is actually the coil in a toaster, a resistorthat's not effectively heat-sunk and is trying to dissipate 40 watts willdefinitely get very hot, and could even shatter, spraying little bits ofhot carbon dust all over the place.Be careful.
What are the 2 uses of variable resistor?
User controls Preset adjustment
DC voltage of 120 volts is feeding series circuit consisting of 2-ohm 6-ohm and 8-ohm regular resistors a variable resistor For line ammeter to indicate 1.5 amp the variable resistor must be fixed?
If the DC voltage of 120 volts is feeding series circuit consisting of 2-ohm, 6-ohm, and 8-ohm regular resistors, the variable resistor for line ammeter to indicate 1.5 amp, the variable resistor must be fixed before the amp.
How many terminals does a variable resistor normally have?
2 terminals. One is connected to the sliding contact. Other is to the coil of wire.
Kinds of resistors?
1.)Linear Resistor 2.)Non Linear Resistor a.)Fixed Value Resistor b.)Variable Resistor c.)Package Resistor Taking into account compositon: 1.) Carbon piece 2.) Carbon Deposition 3.) High Volatge Ink Film 4.) Metal Film 5.) Metal Glaze 6.) Wire Wound 7.) Ceramic Metal
Uses and basic function of carbon resistor?
i don't know about the uses but i know the advantages of carbon resistors.they are:1.they are compact. 2.they are inexpensive.
How do you calculate the correct resistor value needed using 12vdc to run 6vdc circuit?
You need to drop 6 volts across the resistor. -- The resistor you need is 6/(the current in amps that your 6vdc device uses to operate) ohms. Example: If the device uses 1/2 Amp when it's running, then you need a 6/0.5 = 12-ohm resistor. -- And the power-dissipation rating of the resistor has to be at least 36/resistance watts. Example: For the 12-ohm resistor in the last example, it needs to be a (3-watt or more) resistor.
What is reference variable and explain its uses?
Reference variable is an alias name for a previously defined variable. Its use is that the same data object can be referred by 2 names and then can be used interchangeably.
Two uses for a variable resistor?
1. Control the volume of a speaker, i.e. the volume knob on a transistor radio. 2. If attached to a pedal or door hinge, you could use the measured resistance to determine the angle. This would need some calibration in order to be accurate however.
Which professional uses practical knowledge of science to design and manufacture machines?
Its the 2- ENGINEER what grade r u in?
How would you make a bulb in a circuit shine fainter light suggest 2 ways to do this?
lower the voltage by using a different power source or by placeing a variable resistor in series with the light bulb.
What is the use of variable resistor in schmitt trigger?
AnswerMy thoughts are that it is used to set the trigger point where the trigger fires. That is to say, if the voltage exceeds the reference set point, the trigger will then fire.To independently control the upper threshold and the lower threshold, some Schmitt trigger gates have 2 variable resistors: * a voltage-divider potentiometer, where the center tap selects the "average threshold"* a feedback variable resistor, which adjusts the amount of hysteresis (the difference between the upper threshold and the lower threshold).
Calculate the power used in 2ohm resistor in each what circuits- 1 a 6V battery in series wid 1ohm and 2ohm resistors 2 a 4V battery in parallel wid 12ohm and 2ohm resistors?
1). 6V battery, 1-ohm resistor, 2-ohm resistor, all in series:Total resistance = 3 ohms.Current in the loop = 6/3 = 2 amperesPower dissipated by the 2-ohm resistor - I2R = 8 watts.2). 4V battery, 12-ohm resistor, 2-ohm resistor, all in parallelThe 12-ohm resistor is irrelevant.4 volts across the 2-ohm resistor.Power dissipated by the 2-ohm resistor = E2/R = 8 watts.
