Voltage Vs Current

What is current and Voltage?

A very significant doubt in every engineer`s mind is what are voltage and current and how do we perceive it?

I will try to explain what i understand of voltage and current.

Imagine you take a rock on top of a hill of height 50 m say. You drop the rock from the top. The rock starts falling down freely, touches the ground and leaves a considerable mark on the surface it has landed on. Now we will consider three scenarios:

1. What if I drop the same rock from a height of 25 m or 100 m? The answer is that the impact it will have on the surface it will land will vary. Right? for 25 m the impact will be less and for 100 m it will be more.

2. What if I drop the rock from the top of the hill through a tube which has no air in it(vaccum)? The rock will reach the ground faster than when air was present. This is because the air Resistance was not present in vaccum.

3. What if instead of a rock i dropped a feather? There would be no impact on the surface where it falls.

So now let us draw the analogy:

The height of the hill from which you are dropping the rock is the Voltage

The product of the mass and velocity (momentum) of the object is the Current

More the height of the hill, more will be the velocity at impact,

More the weight of the rock, more will be the impact.

The air friction is nothing but Resistance.

So Voltage is the origin of current. Without creating the height difference the rock would not have moved.

Resistance is the link between voltage and Current.