plz explain the working of a rheostat as well.
i cannot understand that when there is already a resistance from the load in a circuit, how r we changing this resistance. that cannot be decreased .can it
i am really very confused. plz explain.
[plz no foolery answers. i would prefer some seriousness. its not that i dont like sarcasm or jokes, but just now, i'm really not in a mood .]
2006-10-18 06:12:12 · 5 answers · asked by catty 4 in Science & Mathematics ➔ Physics
calm down. ok. lets get started
i'm assuming u know the basic definitions: conductor, resistance, length, cross-sectional area etc, etc...
Say we have a circuit in which we place a conductor (wire) of R = 5 ohm. now, we wish to continue the experiment with a conductor of 10 ohm, then 15, then 20 and so on. each time we have to change the wire.this becomes irritating. so, we use a rheostat that provides a varibale resistance ie, a reistance that can be changed.
How does it work?
u know that resistance is directly proportional to length.
in a rheostat, as we slide the slider on top (please go to the phy lab and look at one), we increase the lenght of the wire that is included in the conductor, thereby increasing the resistance. if we pull the slider back, we reduce the length and resistance. this simply makes it easier to get variable values of resistance without having o continuously change the circuit.
making a reistance variable simply means that we can change the reistance as and when we like without having to change the conductor.
a rheostat consists of a conductor wound in spirals. as we move the slider, the more part of the wire is included in the circuit.
http://encarta.msn.com/encnet/refpages/search.aspx?q=rheostat&Submit2=Go
2006-10-18 06:47:41 · answer #1 · answered by sushobhan 6 · 0⤊ 0⤋
There are circuits where you need to be able to adjust something. Volume controls, frequency controls, brightness....stuff like that. The most common way in older stuff to adjust those things is by changing resistance somewhere. Putting a variable resistor that you can turn into the circuit is a whole lot easier than soldering a different resistor in every time you want to change the volume or something.
2006-10-18 11:33:11 · answer #2 · answered by Nomadd 7 · 0⤊ 0⤋
you're ideal that the resistance in a given length of cord won't be able to easily be replaced devoid of fixing temperature. in spite of the undeniable fact which you would be able to alter resistance on a circuit via including something like a rheostat. The rheostat is a loop of cord with a sprint factor. you adjust the resistance of the rheostat via shifting the touch factor larger or decrease on the loop (making much less cord to return and forth). image having a slinky with a cord on one end and a connector you could connect at any factor. Connecting to the far end is various resistance (greater slinky to circulate by using), connecting farther down is way less resistance.
2016-12-26 22:30:34 · answer #3 · answered by ? 3 · 0⤊ 0⤋
A volume control on your stereo needs a variable resistance to control the volume. There are similar applications.
2006-10-18 06:21:33 · answer #4 · answered by Dr M 5 · 0⤊ 0⤋
i dont see the sense in your question but ill try to answer what i understand. u can make resistance varies in your electrical circuit by changing the length of which the current has to go through. resistance depends on several factors and by altering these factors u can 'make resistance variable'.
2006-10-18 06:28:11 · answer #5 · answered by kalkmat 3 · 0⤊ 1⤋