- This topic has 7 replies, 3 voices, and was last updated 12 years, 8 months ago by
.
-
Posts
-
hello everyone!
i want to know dat what is ground?
why we use grount in circuits?
it is nesessary in circuits?
plz explain it clearly my concept is weak about it
Hi,
Nice question.
Ground is referred to a point in a circuit which has the following properties,
-It can sink or eat whatever current applied to it.
-Since it sinks the entire current applied to it, this point has no potential to generate voltage by sourcing current.
-Hence this point is said to have 0 V.
The ground is necessary in a circuit, since any circuit will work only if the current ‘flows’, and all the current flows from the positive voltage source to ground.
Again since the ground has 0 volt it can be used as a reference point to measure the voltages at different points in a circuit.
Ground is very useful while connecting two seperate power sources together.
Expecting more doubts from you!
why we are using conventional current concept instead of direct current flow , therotically we studied all the voltage will flow from positive to negative , but its not, practically the current flows from negative to positive right.
Hi Umar,
If you ask me, the electrons flow from negative to positive (theoritical current flow direction). But this electron flow is only a phenomenon occurs due to the effect of current.
To justify my answer, there is something called ‘drift velocity’ which is the maximum velocity with which an electron can drift through a conductor. Suppose there is a 1 km long conductor with one end negative and other positive. If you switch on the power supply, theoritically an electron from the negative end will take some time to reach the positive end. But you can instantly sense the effect of current at the ends of 1km conductor.
The conventional current flow has been considered from positive to negative by Benjamin Franklin and we follow the same till today. It had nothing to do with the direction in which the effect of current makes the electrons to flow. Only after so many years the electron flow direction was experimentally found out.
Correct me if I’m wrong.
I want to know why they have change the current direction concept (conventional , directional)?, electron flows from negative to positive right if we use conventional method any advantage behind that, drift velocity is more in negative to positive potential region then direct current is best the name itself suggest direct way to accelerate electrons to move positive region
“I want to know why they have change the current direction”
Hi Umar,
As far as I know, Ben Franklin started the convention of marking the electrical flow direction from positive to negative. He actually choose this direction arbritarly. Only after a centuary passed, it was found that the electric current actually flow from negative to positive along with the discovery of electrons. By that time the direction proposed by Franklin became so used to every one and applied in every electrical publications, even in the polarity marking of the batteries and hence it was impossible to change. That is the reason why we still follow his direction convention and we call it conventional direction of current.
- You must be logged in to reply to this topic.