I'm a B.E 2nd year student.what is voltage&current.i really confused.plz explain me(in detail plz)?

Question

I'm a B.E 2nd year student.what is voltage¤t.i really confused.plz explain me(in detail plz)?

Answer 1

A twelve volt DC car battery supplies 12 volts of electrical pressure between its terminals (even when disconnected from the car).  By connecting the battery into the car and closing a switch you have completed a circuit and electrons can now flow (as a current) through the circuit (due to the electrical pressure).  Voltage is similar to water pressure except the current is electrons rather than water molecules.

Answer 2

short and sweetly saying

Voltage is the cause and current is the result....

Answer 3

Voltage is a difference in electrical potential energy; current is the flow of charge over time.

It can be helpful to think of these in terms of analogy with water piping systems. In order to have water flowing through a system you need both a volume of water and pressure on the water to induce its motion.

In electrical systems, the voltage (a.k.a. electromotive force or emf) is just like the pressure in the piping system; it is the difference in energy which causes the motion of the charges. Similarly, the charges flowing in the circuit are just like the water flowing in the pipes; this happens as a result of the energy difference (voltage or pressure) applied across the system.

Another useful analogy is the fact that the current, or water, flow is much slower than the SIGNAL flow. If you have an electric circuit with an open switch, or a piping system that is pressurized and full of water but with a closed valve, you can start the medium flowing by closing the switch or opening the valve. In both cases the flow starts throughout the system very fast, much quicker than the water or electrons actually travel through the system. The signal, which is the change in conditions resulting from turning it on, flows far faster than the actual medium inside the system.

Potential difference is measured in volts, that is joules per coulomb; and current is measured in amperes, that is coulombs per second.

One final note: never call current "amperage". As Horowitz and Hill say in "The Art of Electronics": 'that is strictly bush league.' However, it's fine to refer to potential difference as voltage. Go figure.

Answer 4

Okk so you are in Btech 2nd year and you don't know what is voltage  and current

The formula for voltage is v=ir  where i is current and r is resistance.

Current can be defined as current is the flow of electrical charges ,usually electrons or electron-deficient atoms.It is measured in amperes

Answer 5

This confusion will be there for somebody even after completion of course... OK the answer is below.

Before going into voltage... current... !#$!@$...

Tell me what will happen when u open a tap... the water comes out... why?

The reason is gravity... This guy (gravity) pulls the water down from tank. That pull is known as pressure. When the water is in tank, it is set to be high pressure compare to tap level. When it is at tap, then it is set to be low pressure.. Always water (or anything in this world) flows from high pressure to low pressure. So this high & Low difference cauces the water to flow known as pressure differece

Now assume high pressure (tank) as +ve terminal.(+ve potential)  

low pressure (tap) as -ve teminal. (-ve potential)

Opening tap as closing circuit (switch on)

Water as electron.

When you open the tap (swith on), due to pressure difference (Potential difference), water(electron) starts to flow...

So this pressure difference is known as Potential difference or Voltage. And flow of electrons is current (but direction is taken as opposite to flow of electronics just to avoid confusions. There is no flow of protons)

Now.. who is gravity here? or who plays the roll of gravity as in the water-tank story.

There are many player for this role.

In case if Generators, one of them is magnetic field. When ever a condutor moves against a magnet, electrons starts to flow.. Look into the following for like for more details...

http://science.howstuffworks.com/electri...

In case of batteries the scene is different. Here potentail difference is produced by storing the charges (+ve & -ve) separately. This is similar to pump the water from ground tank to upper tank by a elec.pump. (Gravity is not a reason here. Pressure difference is produced by elec.pump itself.)

Look into the following for like for more details...

http://electronics.howstuffworks.com/bat...