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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

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
I know this work
salma
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
Abhi
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
ninjadapaul
20/(×-6^2)
Salomon
okay, so you have 6 raised to the power of 2. what is that part of your answer
ninjadapaul
I don't understand what the A with approx sign and the boxed x mean
ninjadapaul
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
Salomon
I'm not sure why it wrote it the other way
Salomon
I got X =-6
Salomon
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
ninjadapaul
oops. ignore that.
ninjadapaul
so you not have an equal sign anywhere in the original equation?
ninjadapaul
hmm
Abhi
is it a question of log
Abhi
🤔.
Abhi
I rally confuse this number And equations too I need exactly help
salma
But this is not salma it's Faiza live in lousvile Ky I garbage this so I am going collage with JCTC that the of the collage thank you my friends
salma
Commplementary angles
Idrissa Reply
hello
Sherica
im all ears I need to learn
Sherica
right! what he said ⤴⤴⤴
Tamia
hii
Uday
hi
salma
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
Kim
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Al
y=10×
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
AMJAD
what is system testing
AMJAD
what is the application of nanotechnology?
Stotaw
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
Azam
anybody can imagine what will be happen after 100 years from now in nano tech world
Prasenjit
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
Azam
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
Prasenjit
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
Damian
silver nanoparticles could handle the job?
Damian
not now but maybe in future only AgNP maybe any other nanomaterials
Azam
Hello
Uday
I'm interested in Nanotube
Uday
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
Prasenjit
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
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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