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## Class 10 Physics (India)

### Course: Class 10 Physics (India)>Unit 3

Lesson 1: Electric current & circuit

# Intro to current (& Amperes)

Let's explore what electric current is, how we calculate it, and it's unit (Amperes) and it's direction. Created by Mahesh Shenoy.

## Want to join the conversation?

• Does positive charge move? Aren't protons stationary?
• A good question Ayra.

While coming into current flow, we only consider the flow of electron both in conductors and in semiconductors.
In semiconductors , the flow of holes is actually the flow of electrons in opposite direction.
In conductors when a potential difference is applied the electrons flow from cathode to anode, While we consider the current to flow in just opposite direction.
So there is no motion of protons involved in current flow. It's just electrons, Though it's seemed to be contributed by some positive charge. Hope you understood. :)
• Is Electric Current a scalar quantity? If yes, Please clarify me as at Mahesh sir has told: "The direction of electric current we choose is the direction in which a positive charge moves"
This statement implies Electric current is a vector quantity since it has a direction.
• I think he means positive charge as in a proton
(1 vote)
• Is it only for me or are the subtitles in a different language
?
• what is meant by free electrons
(1 vote)
• A free electron is an electron that has been knocked out of an orbit of a particular atom, or it could be an electron that has been emitted via radioactive decay, or is fleeing from a collapsing star. It is essentially an electron that has been knocked out of an orbit and has yet to be picked up by another atom.
• Is conductivity based on how easily a substance can lose electrons?