My apology for the self-enforced rest from this blog. Well, because of H1N1 …some people pronounce it HINI!… Right, no use ranting and raving, now straight to the point.

Temperature Scale

A thermometer has two fixed points:
the fixed lower point ( ice point) is the temperature at which pure ice and water exist in thermal equilibrium at 1 atmosphere pressure. Its temperature is 273.15 K = 0 ⁰C = 32 ⁰F.
The fixed upper point (steam point) is the temperature of water when it exists in thermal equilibrium with steam at 1 atmosphere pressure. Its temperature is 373.15 K = 100 ⁰C = 212 0F. (This is because for the Celcius scale, there are 100 equal divisions between 0 (ice point) to 100 (steam point), while for Fahrenheit scale, there are 180 equal divisions from 32 (ice point) to 212 (steam point).

In addition to these two , is the Triple Point of Temperature. At this triple point, matters exist in the form of solid, liquid and gas simultaneously. The triple point of water is 273.16 K or 0.01 ⁰C.

Thermometers
I’ll describe 6 of them below:
*op = temperature operating range

1.Mercury thermometer = op – 39 ⁰C to 357 ⁰C
2.Constant Volume Gas Thermometer = -270 ⁰C to 1500 ⁰C
3.Thermocouple = -150 ⁰C to 1150 ⁰C
4.Resistance Thermometer = 180 ⁰C to 1770 ⁰C
5.Thermistor = -70 ⁰C to 300 ⁰C
6.Optical Pyrometer = ambient to almost 3000 ⁰C

wassalam.

Today we’ll look at a technique of linear graph analysis called the least square fitting method. Why do we need to find a best fit line to a set of data in the first place? Because a graph is used to show whether there is a relation between the dependent variable (y-axis) and the independent variable (x-axis). In view of the lab practical that you carried out last week, we’ll plot the best fit line using the spreadsheed software Microsoft Office’s Excel. If you’re a fan of open source software, you could always use OpenOffice.org’s Calc (as useful as Excel, and it’s free).

Download the file  “Least squares fitting with Excel” (in pdf format) and open the file in your local computer.
least-squares-fitting-with-excel.

Having said that, if the example in the aforementioned file is too complicated (it is!!) then try this one.It’s more forgiving on your brain….save you guys the headache.. Click the following url linest.

Ok,this is your gift. song-for-you1

And then, there ‘s chapter 30 on Communicating Information. Click on this: Radio

Here’s some preview:

Direct Sensing : understand that an electronic sensor consists of a sensing device and a circuit that provides an output voltage. In between, the processing unit will process the input picked up by the sensor, and sends this processed signal to an output device. LDR is usually built from CdS (cadmium sulphate) sandwiched between two metal electrodes.  Then sketch the temperature characteristic of a negative temperature coefficient thermistor. Understand what does a transducer do and explain the way sound wave is transferred electrically via a microphone and speaker.

mass of H or p+

(Errr…go where?)

Or, you may download it HERE. (click me!click me!click me!)
To Fara and Farhan, thanks for pointing out the mistakes in the notes.

Too small? Click here>> physics paper 1 2006.

This slideshow defines isotope and some of the elements with their isotopes.

Incidentally, we define the mass of all these periodic elements in terms of

unified atomic mass unit (u).

It is given that 1 u = 1.66 x 10 ^-27 kg.

Say that the atomic mass of silver (Ag) is 107.868 amu. This can also be expressed as

‘the relative atomic mass of silver is 107.868 g per mole”, or simply 107.868.

For your entertainment….

It’s on the model used to describe atomic structure.

What is an isotope?

Atoms whose nuclei has the same number of protons but different numbers of neutrons. Isotopes are chemically identical (since their  electron numbers are identical) even though their nuclei have different masses.