Thank You, Aruki Tsuzukeyou for Your Inspiration.

Physics Form 5: Chapter 4 - Transistor as an Amplifier

An amplifier circuit

I_B = base current

I_C = collector current

I_E = emitter current

V_BB = base voltage 
V_CC =  collector voltage

The function of resistant R_B is to control and limit the base current.

How transistors function as an amplifier:

• The forward-bias from base to emitter narrows the base-emitter,BE depletion layer.
• The reverse-bias from base to collector widens the base-collector, BC depletion layer.
• The free electrons from emitter diffuse easily through the forward-biased BE junction into the p-type region.
• The base region is lightly doped and very thin, so it has a limited number of holes. Therefore, only a small percentage of the all electrons flowing through BE junction can combine with the available holes in the base region.
• Most of the electrons do not combine with holes but diffuse into BC depletion layer.
• Once here, these electrons are pulled through the reverse-biased BC junction by the electric field set up by the force of attraction between the positive and negative ions.
• Electrons now move through the collector region and into the positive terminal of the collector voltage source.
• This forms collector current which is larger than the base current.

Click on the diagram below to play!

 Conclusion:

When there is a small change in the base current, there will be a big change in the collector current. 

Chemistry Form 5: Chapter 3 - Redox Reaction in Electrochemistry Reaction

• More electropositive metal undergoes oxidation reaction by releasing electrons and act as a reducing agent.
• Less electropositive metal undergoes reduction reaction by gaining electrons and act as a oxidising agent.
• Electrons flow from more electropositive metal to less electropositive metal.

Physics Form 5: Chapter 4 - How Transistor Works

The design of a transistor allows it to function as an amplifier or a switch. This is accomplished by using a small amount of electricity to control a gate on a much larger supply of electricity, much like turning a valve to control a supply of water. 
Transistors are composed of three parts – a base, a collector, and an emitter. 

Base = gate controller device for the larger electrical  supply.
Collector = larger electrical supply.
Emitter = outlet for electrical supply.

By sending varying levels of current from the base, the amount of current flowing through the gate from the collector may be regulated. In this way, a very small amount of current may be used to control a large amount of current, as in an amplifier. The same process is used to create the binary code for the digital processors but in this case a voltage threshold of five volts is needed to open the collector gate. In this way, the transistor is being used as a switch with a binary function: five volts – ON, less than five volts – OFF. 

Still Can't Understand How Transistor Works! 

Try this imagination! 

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We provide a reservoir of water for "C" (the "power supply voltage") but it can't move because there's a big black plunger thing in the way which is blocking the outlet to "E". The reservoir of water is called the "supply voltage".

If we increase the amount of water sufficiently, it will burst our transistor just the same as if we increase the voltage to a real transistor. We don't want to do this, so we keep that "supply voltage" at a safe level.

If we pour water current into "B" this current flows along the "Base" pipe and pushes that black plunger thing upwards, allowing quite a lot of water to flow from "C" to "E". Some of the water from "B" also joins it and flows away.

If we pour even more water into "B", the black plunger thing moves up further and a great torrent of water current flows from "C" to "E".

Physics Form 4: Chapter 3 - Application of Bernoulli Principle ( Aerofoil )

A cross section of a typical airplane wing will show the top surface to be more curved than the bottom surface. This shaped profile is called an aerofoil or airfoil. 

 

Due to this aerofoil structural design, the difference pressure below and above the aerofoil able to produce a larger lifting force.

According to Bernoulli Principle:

• Air moves with higher speed over the top of aerofoil.
• This creates a region of lower pressure over it and a region of higher pressure below it.
• This difference in pressure produce a resultant force acting upwards on the wings.

Drag is the resistance of air (the backward force), thrust is the power of the airplane's engine (the forward force), lift is the upward force and weight is the gravity downward force.

When it is in straight and level flight the opposing forces of lift and weight are balanced. During a descent, weight exceeds lift and to slow an airplane drag has to overcome thrust. 

Chemistry Form 4: Chapter 6 - Constructing Electrochemical Series based on the Potential Difference between Two Metals

• In a voltaic cell, two different metals are used to create a potential difference.
• A higher metal in the electrochemical series will be made negative terminal.
• A lower metal in the electrochemical series will be made positive terminal.
• Conversion of energy is chemical energy to electrical energy.

Metals which are further apart in the electrochemical series produce a higher voltage than metals which are close to each other.

 By arranging the metals in order of their voltage readings, you can build up the electrochemical series.

Click on the diagram below to play!

Penang Assam Laksa Top 10 Global Food

Penang are proud to have Datuk Lee Chong Wei as World No.1 badminton man's single player, Datuk Nicol David as World No.1 squash woman's player, Jimmy Choo as world renowned shoe designer and many more towering Penangites who make Penang famous..

Now, we have Penang aunties and uncles who cook wonderful and delicious street food making Penang on the world map again. Without them, we will not have a chance to eat delicacy food such as assam laksa, har me, char kuey tiao, lobak, pasembur, hokkien me, bak kut teh, nasi kandar and so on. Thank you so much. Ah yi and Ah chek!

Let's we protect and promote our street food heritage!

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KUALA LUMPUR, July 25 — Spicy, sour, fruity and fragrant, Penang assam laksa was voted seventh out of 50 most delicious food in the world in a global poll that leaned heavily towards Asian flavours. Malaysia’s sole entry beat out Indonesia’s beef rending (No 11) and Singapore’s twin national dishes, chicken rice (45) and chilli crab (35), but fell behind Thailand’s massaman curry, which took top spot.

The recent CNN Go feature did not say how it came up with the list, apart from saying its writers had “scoured the planet” for what they thought were the top 50 “foods worth travelling the world to gorge on”. “Poached, flaked mackerel, tamarind, chili, mint, lemongrass, onion, pineapple . . . one of Malaysia’s most popular dishes is an addictive spicy-sour fish broth with noodles (especially great when fused with ginger), that’ll have your nose running before the spoon even hits your lips” was how the online lifestyle feature described Penang assam laksa.

But Malaysia’s northern neighbour appeared highly popular with the CNN Go writers, as it saw four different dishes finding its way into the list. Apart from the massaman bestseller, Thailand also scored top marks for tom yum goong (No 8), nam tok moo, a meaty dish of grilled pork and toasted rice (No 19), and its signature green papaya salad, som tam (No 46).Other Southeast Asian offerings include Vietnam’s pho (No 28) and goi cuon, a rice-paper roll of shrimp, herbs, rice vermicelli and other ingredients, much like Malaysia’s poh-pia. The top 50 also feature a number of “national foods” such as sushi from Japan and Britain’s fish and chips.

Physics Form 4: Chapter 3 - Application of Archimedes Principle (Plimsoll Line)

Plimsoll line is a mark on a vessel’s side indicating the maximum depth to which it may be safely immersed when loaded with cargo.

The maximum safe loading depth varies with ocean regions and seasons. In the tropics the water is warmer and therefore less dense than in temperate regions, so with the same load ships will float higher in cold regions than in the tropics. Summer and winter cause similar changes.

• The density of water is determined by the salinity of water at different locations
• A ship will submerge deeper in freshwater than that in sea water because the density of freshwater is smaller. 
• The ship can be loaded with heavier load in sea water than in freshwater.