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ILC title


3. Technical Basics

3a Units of measurement and multiple/sub-multiple prefixes.

3a.1 Recall the units and abbreviations for potential difference, current, power, resistance, capacitance, inductance and frequency.

The ILC will be taking you much much deeper into electronic theory than the FLC and the course will assume that you have a good working knowledge of all of the FLC technical basics. Some revisions will be given but mainly the ILC will be new information that needs to be fully understood stage by stage before passing onto the next part. So don't rush your learning and remember to chat to your course tutor about anything that is not clear. Even if you think that you are asking a silly question "ASK IT" !!

In this part of the syllabus is going over five items that you learned (or should have learned) in the FLC and only introducing two new items. 

However it has come to our notice that some students do not know the units of resistance, inductance, capacitance etc. These unit must be learned so that they are second nature to you so that in a question such as :-

The value of a capacitor is given in ?  You readily know to tick the box next to  Farads.

Quantity

Symbol

Units

Comment
Potential Difference

V

Volts (V) Learned in FLC
Current

I

Amps (A) Learned in FLC
Resistance

R

Ohms The symbols for ohms Learned in FLC
Power

P

Watts (W) Learned in FLC
Frequency

f

Hertz (Hz) Learned in FLC
Capacitance

C

Farad (F) New for ILC
Inductance

L

Henry (H) New for ILC

Recall and understand the prefixes pico, nano, micro, milli, kilo, Mega and Giga.

In the FLC you learned about milli kilo and Mega - m,k,M so there are four new ones to learn.

Prefix

Prefix Name

Scaling

Example Comment

p

pico

1/1,000,000,000,000

0.000000000001

1pF

1 pico farad New for ILC

n

nano

1/1,000,000,000

0.000000001

1nF

1 nano farad New for ILC

u

micro

1/1,000,000

0.000001

1uF

1 micro farad New for ILC

m

milli

1/1,000

0.001

1mA

1 milli amp Learned in FLC

1

k

kilo

1000

1kThe symbols for ohms

1 kilo ohms Learned in FLC

M

Mega

1,000,000

1MThe symbols for ohms

1 mega ohms Learned in FLC

G

Giga

1,000,000,000

1GHz

1 giga hertz New for ILC

You need to be able to convert between one prefix and another. NOTE: that the interval between the changes is 1,000 whichever way you are going !!!


Some students find it difficult to convert down the scale from larger to smaller numbers when it is less than 1  -- perhaps the following will help.

  • 1
  • 0.001

  • 0.000001

  • 0.000000001

  • 0.000000000001

  • Unit
  • milli
  • micro
  • nano
  • pico
  • 1 = 1
  • 1000 milli = 1
  • 1000 micro = 1 milli
  • 1000 nano = 1 micro
  • 1000 pico = 1 nano
Try to see the pattern in the numbers and write out how to convert from one to another in the way you can understand.

Try with the example below. To start with always relate the number to 1

Example

Convert 0.001 micro to nano farads ?

So relative to 1 farad we have  from above :-

1 micro farad = 0.000001

Thus relative to 1 farad 0.001 micro farads = 0.00000001

we have added the extra 3 zeros  one for the decimal point and the other two from the 001

We now have 8 zeros

from above we know that

relative to 1 farad that 1 nano farad = 0.000000001

that is 8 zeros so 0.001 micro farads = 1 nano farads.

A student (from an early course who has now progress to an Advanced licence) suggested the following to help you remember the order down from the biggest to the smallest,

Goal Makers Kick Once Many Underestimate Noise Pollution

Goal = Giga

Makers = Mega

Kick = kilo

Once = 1

Many = milli

Underestimate = u for micro

Noise = nano

Pollution = pico

At Intermediate level you need to recall the Engineering Notation for key units and sub-units and be able to change between them, but there will be no calculations requiring you to use the notation.

The three zero steps in the units and sub-units translate into changes of x 103 with each level of unit or sub-unit:

Giga = x 109

Mega = x 106

Kilo = x 103

Milli = x 10-3

Micro = x 10-6

Nana = x 10-9

Pico = x 10-12

However at Intermediate level you need to recall the Engineering Notation for key units and sub-units and be able to change between them, but there will be no calculations requiring you to use the notation.


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