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Resistors are not usually given 'current ratings' but, rather, 'power ratings' expressed in submultiples of the watt. It is then up to the user to calculate the safe maximum operating current for a particular resistor, by manipulating the equation: P = I2 R.
Since a power rating is dependent upon the resistor's ability to dissipate energy by heat transfer, the actual power rating is dependent upon the surface area and, hence, the physical size of the resistor. So you will find that resistors come in a variety of physical sizes for any given resistance value.
Unfortunately, power ratings are not indicated through colour codes, etc., so you will have to either specify its power rating when you purchase a resistor, or match your existing resistor against a scale-drawing to determine its power rating.
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A can be used to reduce the current in a circuit?
A resistor.
What is the voltage drop across a 100 W resistor when the electric current flowing through it is measured at 250 mA?
Who can tell? The power rating of a resistor simply tells us the maximum power that resistor is capable of handling; it doesn't tell us anything about the actual power being produced for any given current. So, to find out the voltage drop across that resistor, you will need to find out its resistance, and multiply this value by the current you specify.
What is series dropping resistor?
A series dropping resistor is a resistor that limits the amount of current flow in a circuit.
Resistors A and B are connected in parallel If resistor B has twice the resistance of A what is the current taken by resistor B?
half of the current flowing thru resistor 1.... V=IR.
What component that makes it more difficult for current to flow?
IF there is a Resistor
How do you connect in order to produce a maximum current in a given external resistor?
in parallel
What is the current flowing through a 200 watt resistor that has a rating of 21 ohms?
The current can't be calculated from the information given in the question.The power rating of a resistor is the maximum power it can dissipate before it overheatsand its resistance possibly changes permanently. The power rating is not the amount ofpower it always dissipates.So, all we really know about the resistor in the question is that its resistance is 21 ohms.And all we can say about the current through it is:Current through the resistor = (voltage between the ends of the resistor) divided by (21).
What is the formula of calculating effective current if resistor and voltage is given?
I = E/R or Current = Voltage/Resistance (Ohm's Law)
What is the unit of the resistors?
Resistor values are given in ohms. A value may be selected to deliver a specific current at a given voltage. This is given in what is known as Ohm's Law where: Voltage (V) = Current (A) X Resistance (Ohm) A 12ohm resistor placed across a 12V battery would pass 1Amp of current and put out 12W of heat.
What is the unit of measures for resistors?
Resistor values are given in ohms. A value may be selected to deliver a specific current at a given voltage. This is given in what is known as Ohm's Law where: Voltage (V) = Current (A) X Resistance (Ohm) A 12ohm resistor placed across a 12V battery would pass 1Amp of current and put out 12W of heat.
How micro ohm meter work in detail?
A current is passed through a resistor and the voltage drop is measured on the other side. It follows Ohm's law by a given current and voltage you can measure the resistance of a resistor by V=IR.
What is the current through the 4000Ω resistor in mA?
Without more information on the circuit this resistor is in, no answer can be given. This sounds like a homework question, where a schematic is given in the book. Please consult the schematic in your book and you should be able to answer it for yourself.
A can be used to reduce the current in a circuit?
A resistor.
What is the potential difference across a 1500 ohm resistor carrying a current of 0.075 A?
Potential Difference across a resistor is given by, Potential Difference = Resistance * Current = 1500 * 0.075 = 112.5 Volts
Is current is drop when it flowing through the resistor?
Current flows in loops, voltage drops across elements. With relation to current, what flows in, must flow out, so no, current is not dropped across a resistor, it flows through a resistor and voltage is dropped across the resistor.
What is a ballast resistor?
A ballast resistor is an electrical resistor whose resistance varies with the current passing through it, thus maintaining a constant current.
Basic concept of resistor?
resistor is to resists the flow of current
