Skip to main content

6.2 What is Voltage?

Description:


  • The electrons in a conductor (copper for example) freely move from atom to atom, but in a completely random way. 
  • Motion of free electrons is normally haphazard. So, a sort of pressure or push helps electrons to move in a particular direction. 
  • The technical term for this pressure or push is electromotive force, EMF for short or sometimes simply E. It creates pressure on the electrons which channelizes them to flow in a single direction. But you know it more commonly as voltage.

Voltage:

  • Voltage (V) is the unit of potential difference. More clearly, voltage is the difference in potential, between two points. 
  • Basically, to find the difference, we need two points. Similarly, to measure volt we need two points. Let A and B are the two points connected through any conducting material.

  • Potential of A is 50 and B is 30 and the unit of potential is coulomb (Q). ‘Point A’ has high potential which means more electrons. ‘Point B’ has low potential which means less electrons. And the difference between these two points is the Voltage. In this case 50 Q – 30 Q = 20 V
  • As the points are connected with a conductor such as a copper wire, that forms a circuit through which electric current will flow. 
  • This current continues to flow until all the extra negative charges on the negative side of the circuit have moved to the positive side. When that has happened, both sides of the circuit become electrically neutral and the current stops flowing.


Current:

Scenario 1: 50 Q – 30 Q = 20 V

Scenario 2: 50 Q – 50 Q = 0 V

i.e., difference between 50 coulomb and 30 coulomb is 20 volts but when there is equal potential at both the points, then there is zero volt which means no current. Thus, voltage creates the potential for current to flow. If current can be compared to the flow of water through a hose, voltage can be compared to water pressure at the faucet. It’s water pressure that causes the water to flow in the hose.

Flow of electrons from high potential (A) to low potential (B) at a particular point per second is the current(I) measured in Ampere(A) or in other words Charges (coulomb) crossing through point C per second is the ampere. 

Ampere (A) = 1 Coulomb1 Second

If five units passes through point C for one second the its 5 Ampere.


Just few extra Information:

  • Conventional current flow means that current flows from positive to negative. Thus, the current flows from the positive terminal of the battery through the lamp and then back to the negative terminal of the battery. 
  • In reality, conventional current flow is opposite of the actual flow of electrons through the circuit. The negative side of the battery has an excess of negatively charged particles (extra electrons / high potential) whereas the positive side has an excess of positively charged particles (missing electrons). Thus, the electric charge flows through the conductor from the negative side of the battery, through the lamp, and back to the positive side.


Pre-requisites for the current to flow in a conductor:

  • Circuit needs energy source (battery for instance) that produces voltage.
  • Without voltage, (pressure) electrons flow randomly and undirected, hence current cannot flow.
  • Voltage creates pressure on the electrons which channelizes them to flow in a single direction


Read the next post: 6.3 What is Resistor? 

Labels:

Comments

Post a Comment

Popular posts from this blog

7. What is Arduino Nano

The Arduino Nano is a microcontroller.  The Arduino Nano is Arduino’s classic breadboard friendly designed board with smallest dimensions. The Arduino Nano comes with pin headers that allow for an easy attachment onto a breadboard and features a mini-B USB connector. It is an intelligent development board designed for building faster prototypes with the smallest dimension. Oldest member of Nano family. Enough interface for breadboard friendly applications Heart – Atmega328 microcontroller Clocked at a frequency of 16MHZ Same functionalities as the Arduino Duemilanove. 22 digital pins. 8 analog pins. A mini USB port. First embedded micro-controller in the Nano series   Features: High performance low power 8-bit processor. Achieve up to 16 MIPS for MHZ clock frequency. Flash memory – 32 KB of which 2 KB used by bootloader. Internal SRAM – 2 KB EEPROM – 1 KB PWM Channels – 6 Power: Mini – B USB Connection 6-20 Unregulated external po...
Post a Comment
Read more

2. Working Principle of Internet of Things

Consider reservation counters and banks for example: Typical computer system work on the principle, Input-->process-->output. In conventional system input is keyed in by human beings. The software algorithm running at the computing system, process the input data and produces an output. If people responsible are lethargic or lazy, often the speed and accuracy of the system is lost. But in IoT we do not have this issue. Inputs are replaced by relevant sensors. Hence possibility of human error can be eliminated to the great extent. Processing happens in cloud and returned to receiver end. Block diagram of the process-flow: In many IoT systems, sensors forward data via short-range wireless communication protocols such as Bluetooth, zigbee, wifi to the local computing system. Data gets pro-processed and sent to the central server or the cloud system. Analytics software system takes informed decisions at the cloud platform and will reach the receiver end device.  In few cases this ...
Post a Comment
Read more

6.5 Capacitor and Capacitance

  Description:  Capacitance is the capacity or ability of a capacitor to store electrical energy. Capacitor is a component to store and discharge energy. The other name for capacitor is condenser. Image shows different variants of Capacitor Working: The capacitor is made up of two close conductors (usually plates) that are separated by a dielectric material. The plates accumulate electric charge when connected to power source. Once the battery is connected, negative charges on the right side gets attracted towards the positive terminal of the battery and on the left side, negative charges gets repelled away from the negative terminal of the battery. As the negative charges leaves the piece of metal in the right, it makes that piece of metal positively charged, and the piece on left becomes negatively charged. Both sides has same magnitude of charge. As the plate on the right becomes positively charged, the next electron gets confused where to move, whether to the positive term...
Post a Comment
Read more