0
A resistor, of which a rheostat is, has a maximum amount of current it can handle. Beyond that value it will start heating up a lot and might burns up. Since, the maximum resistance of a rheostat is fixed so does its maximum safe current value that can flow through it.
Comment'Rheostats' and 'potentiometers' describe applications of variable resistors; they are not alternative words for variable resistors.
What else can I help you with?
Formula used to find the maximum current that can be carried by a resistor if resistance and wattage rating is known?
Manipulate the following equation, to make I the subject: P = I2R, where P = power, I =current, and R = resistance.
What happens to the current as the resistor approches infinty?
Most resistors are linear, or 'ohmic', devices -which means that they obey Ohm's Law. So the ratio of voltage to current remains constant for variations in voltage. In other words, their resistance remains constant -providing their power rating isn't exceeded. So you can say that, providing the current increase doesn't cause their power rating to be exceeded, their resistance should remain the same. Resistors wouldn't be of much use if their resistance value changed whenever the current through them changed!
What is the fire resistance rating for 8th inch steel plate?
Unprotected steel is generally not recognized as having a fire resistance rating.
What is the current being drawn by a 100W light bulb and what is the resistance of a 100W light bulb?
Assume the rating of 100W refers to operation on a supply of 117 volts.Power = (voltage) x (current)Current = (power) / (voltage) = 100/117 = 0.855 ampere (rounded)Power = (voltage)2 / (resistance)Resistance = (voltage)2 / (power) = (117)2 / 100 = 136.89 ohms
Why current rating of diode is given but voltage rating is not given?
In the forward direction the effective resistance of the diode is essentially zero. By Ohm's Law Voltage = Current x Zero. However, in a reversed bias situation there is typically a breakdown voltage that could destroy the device or in some cases cause a reverse current to flow as part of the circuit design.
Why rheostats have current ratings in additing to resistance rating?
So you don't try to put in more current than they can handle - so they don't catch fire.
How do you compute wattage?
Wattage or power rating of a product can be calculated by multiplying voltage rating and current rating. (Power = Voltage x Current). e.g. if device is working at 12V and 2A is the current rating. It is 24Watt. Since Voltage = Current x Resistance , for a resistive load power can also be calculated by Power = Current x Current x Resistance = I^2 x R = I square R
Formula used to find the maximum current that can be carried by a resistor if resistance and wattage rating is known?
Manipulate the following equation, to make I the subject: P = I2R, where P = power, I =current, and R = resistance.
Does current or resistance cause breakers to trip?
Excessive current is what causes circuit breakers to trip. When the current in a circuit exceeds the rating of the breaker, it trips to prevent overheating and potential fire hazards. Resistance itself does not cause breakers to trip, but it influences the amount of current flowing in a circuit.
What should be the current rating of a 120VDC 0.4A temperature switch at 24 V DC?
0.4A. The power dissipated in the switch and therefore how hot it gets depends on the current and the resistance.
What happens to the current as the resistor approches infinty?
Most resistors are linear, or 'ohmic', devices -which means that they obey Ohm's Law. So the ratio of voltage to current remains constant for variations in voltage. In other words, their resistance remains constant -providing their power rating isn't exceeded. So you can say that, providing the current increase doesn't cause their power rating to be exceeded, their resistance should remain the same. Resistors wouldn't be of much use if their resistance value changed whenever the current through them changed!
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).
Why rheostat have current ratings in addition to resistance ratings?
So you don't try to put in more current than they can handle - so they don't catch fire.
Why is ideal resistance of a voltmeter infinity?
generally voltmeters are connected in parallel in the circuit.If the voltmeter resistance is lower as it increases the current rating,because by connecting parallel we are decreasing the resistance,so if the voltmeter resistance is not too much higher it leads to burning of the meter,For that we can conclude that the in ideal the voltmeter has infinite resistance.
What is the fire resistance rating for 8th inch steel plate?
Unprotected steel is generally not recognized as having a fire resistance rating.
What is the current being drawn by a 100W light bulb and what is the resistance of a 100W light bulb?
Assume the rating of 100W refers to operation on a supply of 117 volts.Power = (voltage) x (current)Current = (power) / (voltage) = 100/117 = 0.855 ampere (rounded)Power = (voltage)2 / (resistance)Resistance = (voltage)2 / (power) = (117)2 / 100 = 136.89 ohms
What is the rating of The Grey?
Resistance grey=8
