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Technology

Grade 8

Electricity

Module 15

Important measuring units

Activity 1

To be able to explain the most important measuring units and their mutual connection

LO 2.4

We have already said that an electrical current is the flow of electrons in a circle. The speed at which the electrons flow, is measured in Ampère. In order to measure amperage, one must allow the current to flow through an Ammeter.

The battery supplies the energy that is also called the electromotive force (EMF ). It is measured in Volts . In order to measure voltage one must place the two points of a voltmeter on either side of a component.

Resistance is offered against the flow of the current and the resistance is measured in Ohms .

A battery does not provide its full energy because some of its energy is lost. This is called power and it is measured in Watts .

Ohm’s law states that the current through a resistor is directly proportional to the tension that is coupled over a resistor, i.e. the current is directly proportional to the tension and inversely proportional to the resistor. It is formulated as follows:

I = V / R

Actuation is the energy that must supply the battery and is wasted as heat in a resistor. It is formulated as follows:

P = V x I

  • Summary of electrical units
Symbol Unit Abbreviation
TENSION V Volt V
CURRENT I Ampère A
RESISTANCE R Ohm Ώ
POWER P Watt W

The formulas make it possible for one to determine units through mathematical computations, e.g. if one has the Volts and Ampère of a circuit, one can calculate the power. Nowadays we use advanced apparatus to measure current, tension and resistance.

  • The multimeter is such a device. If your school owns one, you will have the opportunity to take readings with it.

Assignment 1

1. Provide two more formulas that can be derived from the formula I = V / R.

2. Provide two more formulas that can be derived from the formula P = V x I.

LO 2.4

Assessment

Learning outcomes(LOs)
LO 2
TECHNOLOGICAL KNOWLEDGE AND UNDERSTANDING The learner will be able to understand and apply relevant technological knowledge ethically and responsibly.
This is demonstrated when the learner:
structures:2.1 demonstrate knowledge and understanding of frame structures:
  • the use and application of basic structural components (columns, beams, arches, buttresses, struts, stays, guys, ties);
  • reinforcing techniques for frame structures (triangulation, webs and fillets, orientation and cross-sectional area and members);
  • how frame structures can be made strong (e.g. relationship between the size and the shape of the base, the centre of gravity and stability;
systems and control:2.4 demonstrates knowledge and understanding of how electrical circuits with more than one input or control device will work based on different logic conditions (“AND” and “OR” logic), and represents them using circuit diagrams, systems diagrams and truth tables.

Memorandum

  • The following definitions are important:
  • Electric current: Flow of electrons in a closed circuit
  • Voltage: Electromotive force that enables the flow of electric current
  • Resistance: Quality of materials offering resistance to the flow of electric current.
  • Power: The energy that a battery has to provide and which is used in a resistor.

Ohm's law:

  • This states that the current passing through a resistor is directly proportional to the potential difference, or voltage, across the resistor, i.e. the current is directly proportional to the linked voltage and inversely proportional to the resistance.

Assignment 1

1. V = I × R and R = V/I

2. V = P/I en I = P/V

3. R = V/I = 3 1,5 size 12{ { {3} over {1,5} } } {} = 2 ohm

4. P = V × I = 3V × 1,5A = 4,5 watt

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Technology grade 8. OpenStax CNX. Sep 13, 2009 Download for free at http://cnx.org/content/col11052/1.1
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