Chitchat "Discover Physics", GCE 'O' Level, by Dr. Charles Chew.

[ChanRasjid]

I have read about how the other countries - even the U.K. - consider our GCE O level syllabus and teaching to be excellent. Many countries seem to have copied our syllabuses.

I have just started to give physics revision to my grandnephew in GCE O level physics and I found this (highlighted):
1) definition: The electromotive force, or emf, of an electrical energy source is the work done by the source in driving a unit charge around a complete circuit.
2) potential difference: The potential difference across a component in an electric circuit is the work done to drive a unit charge through the component.

The above two definitions are simply wrong! emf and potential difference are measured in volts (V), energy is measured in joules (J). The proper explanation should be:"There is work done(W) in moving one unit of charge(Q) through a potential difference(V) in an electrical circuit. The formula is W = V x Q".

Actually, the concept of emf/potential difference is not a trivial concept to explained. As an example, it is said that for every meter difference in height in our atmosphere near the ground, the voltage difference may be 120 volts, yet none of us ever get electrocuted.

quote:"The atmospheric potential gradient leads to an ion flow from the positively charged atmosphere to the negatively charged earth surface. Over a flat field on a day with clear skies, the atmospheric potential gradient is approximately 120 V/m."

So I don't know how to explain to my grandnephew. He has to regurgitate the above wrongs if he is not to be penalized!

Our MOE may like to teach advanced concepts early to our students, but doing it correctly can sometimes be tricky.

And "Discover Physics" is written by a Ph.D. !

"Einstein's E=mc² Is Invalid"
Chan Rasjid Kah Chew,
Singapore.
http://www.emc2fails.com

 

[Patriotmissile]

Nothing is wrong.
E = QV
V = E/Q
E is energy measured in Joule and it is equivalent to Workdone measured in Nm or J.
When doing work, energy is used.

 

[Loofydralb]

That's why I say a true blue Sinkies will never win the Nobel.

 

[sweetiepie]

Imuho sg educational system all the while was having problems. You get kicked out of secondarlee school to VITB for incompetence to sit for gce earn level and oar level and goes to ite to take up subjects more difficult than gce earn and oar level. Doesn't make any sense.

 

[syed putra]

Imuho sg educational system all the while was having problems. You get kicked out of secondarlee school to VITB for incompetence to sit for gce earn level and oar level and goes to ite to take up subjects more difficult than gce earn and oar level. Doesn't make any sense.

The whole idea is to torture the people.
Oar and earn level in the west is a test for competency. Basic test to see if yiu rnderstand the topic.
But if you take oxfart snd cumbridge syllabus its different because they test for brilliance. They want geniuses.
We test for brilliance but end up working ordinary jobs.

 

[sweetiepie]

The whole idea is to torture the people.
Oar and earn level in the west is a test for competency. Basic test to see if yiu rnderstand the topic.
But if you take oxfart snd cumbridge syllabus its different because they test for brilliance. They want geniuses.
We test for brilliance but end up working ordinary jobs.

Well analysed. It looked more towards torturing else they should kicked them out to be a leeleeverlee or labour jobs.

 

[JohnTan]

1) definition: The electromotive force, or emf, of an electrical energy source is the work done by the source in driving a unit charge around a complete circuit.
2) potential difference: The potential difference across a component in an electric circuit is the work done to drive a unit charge through the component.

I doubt PAP would fuck up sinkies education, unlike oppies. Here's what the good white people have to say about emf.

EMF (ϵ) is the amount of energy (E) provided by the battery to each coulomb of charge (Q) passing through.

https://www.birmingham.ac.uk/teachers/study-resources/stem/physics/electromotive-force.aspx

 

[sweetiepie]

The whole idea is to torture the people.
Oar and earn level in the west is a test for competency. Basic test to see if yiu rnderstand the topic.
But if you take oxfart snd cumbridge syllabus its different because they test for brilliance. They want geniuses.
We test for brilliance but end up working ordinary jobs.

All bullshit one lah. Last time during my uncle's oar level those that failed to qualify for Polytechnic due to not passing English can enrol for Japan sg technical institute JSTI or German sg institute GSI. My uncle browsed through the syllabus is on par with Polytechnic and still need to pass Japanese or German when they cannot even pass English

 

[realDonaldTrump]

The level is pitched at O Levels, so it is inevitable educators Charles has to simplifying things like this.

For example, students learn that Air can be compressed, Solid and Liquid can't. In advanced physics, water can be compressed.

Biased Opinion: Charles's a warm and humble guy whom I came across during Air Force days.

 

[ChanRasjid]

I doubt PAP would fuck up sinkies education, unlike oppies. Here's what the good white people have to say about emf.

EMF (ϵ) is the amount of energy (E) provided by the battery to each coulomb of charge (Q) passing through.

https://www.birmingham.ac.uk/teachers/study-resources/stem/physics/electromotive-force.aspx

Exactly! I did google and notice how this Dr. Charles Chew blindly copied from www.birmingham.ac.uk...
wiki:"In electromagnetism and electronics, electromotive force (emf) is the electrical action produced by a non-electrical source, measured in volts".

I just told my grand nephew trust wiki more (for maths and science), well looked after by moderators. Sometimes, sites are done by unqualified persons - ah-mao-ah-gou!

Volts and joules can never be the same thing or "equality"!

 

[ChanRasjid]

The level is pitched at O Levels, so it is inevitable educators Charles has to simplifying things like this.

For example, students learn that Air can be compressed, Solid and Liquid can't. In advanced physics, water can be compressed.

Biased Opinion: Charles's a warm and humble guy whom I came across during Air Force days.

We are usually informed that liquid is generally incompressible, but not absolute.

Simplifying things is always needed in science, but the concept must not be outrageously wrong! A better explanation: "Emf is the capacity (e.g. battery, solar panels, generators) to cause electric charges to flow within a closed conducting circuits". Emf or potential difference can never be the same as work done!

We always introduced physics concepts as good approximations; e.g. It s well known that Ohm's law given by "R = V/I" to be a good approximate, but not exact - it varies when the V and I ranges go beyond certain limits.

Potential difference is never a trivial concept in physics.

 

[ChanRasjid]

I have now gone through nearly the whole book "Discover Physics". To be fair, the only grave mistakes(grave and fundamental) I found are the two definitions of emf and potential difference - concepts that by themselves are difficult. But no students of physics should ever commit such mistakes!

On the whole, the book is well written. In fact, I am surprise the syllabus covers internal energy of matter, a topic which is even "advanced" for me (I have not read proper thermodynamics). They even gave the distinction between internal potential energy(due to iter-particle bonds) and internal kinetic energy(random motion) of matter (solid, liquids) and noted that only the kinetic part is responsible for temperature increase. I think only the better students could memorize such detail distinction.

This book is only for GCE 'O' level, "physics with Chemistry". Probably, the pure physics would cover more. So my final review is that there is nothing wrong with this MOE syllabus - covers much more then what I had in 1966. Hope our students could take it.

"Einstein's E=mc² Is Invalid"
Chan Rasjid Kah Chew,
Singapore.
http://www.emc2fails.com

 

[mudhatter]

That's why I say a true blue Sinkies will never win the Nobel.

Only Ang Mohs win it coz it's another of those awards whose awardees are chosen -- wait for it -- arbitrarily.




Very scientifically correct and objective method.

 

[mudhatter]

Imuho sg educational system all the while was having problems. You get kicked out of secondarlee school to VITB for incompetence to sit for gce earn level and oar level and goes to ite to take up subjects more difficult than gce earn and oar level. Doesn't make any sense.

true

but it doesn't change anything


slanties anywhere under any system have always lagged superior inventive caucasoids which are few and far between but still superior to mongoloids who are totally barren as far as inventiveness and originality goes. just copy cut and paste.

why didn't japs surpass yanks geopolitically in mid 1990s? yes coz they are genetically inferior?

why don't slanties born and bred and raised in anglo countries like us uk can aus nz surpass their ang moh peers in being inventive pioneering and have the ang mohs and other races ape them, instead of them aping the ang moh kias and seeking their attention and approval for any little thing?

obviously coz they know it very well, the truth is slanties are an inferior race to caucasoids, it's a well known, proven fact

 

[JohnTan]

On the whole, the book is well written. In fact, I am surprise the syllabus covers internal energy of matter, a topic which is even "advanced" for me (I have not read proper thermodynamics). They even gave the distinction between internal potential energy(due to iter-particle bonds) and internal kinetic energy(random motion) of matter (solid, liquids) and noted that only the kinetic part is responsible for temperature increase. I think only the better students could memorize such detail distinction.

The book by this Charlie Chew has been vetted by PAP. Of course it will be good! Majulah PAP!

 

[ChanRasjid]

The correct definition of emf (to be recommended for our next parliamentary debate...inform Pritam Singh how MOE messed up big time...):
Emf is the force or capacity of the electrical energy source that give rise to currents in a closed conducting circuit measured in volts.

All over the internet, they try to define emf without calling it a "force" because it seems there is no easily ascertainable force involved in electromagnetism. That's where they got all their definitions wrong. Even wiki's definition is not right as it called emf an "action". The dry AAA cell you hold in your hand still have emf even though it is not in action; the terminals are actually electrical charged(extremely weak static charges) giving a 1.5V.

When a battery is connected and light up a bulb, a uniform electric field is established inside the conducting wire pointing from the _+ve terminal to the -ve. There is a true force acting in the free electrons in the wire, driving it to move counter to the direction of the conventional current direction.

Emf is termed electromotive force by the pioneers not without a reason. Surely not work done!

PAP MOE Wrong! Majulah Workers Party!

"Einstein's E=mc² Is Invalid"
Chan Rasjid Kah Chew,
Singapore,
http://www.emc2fails.com

 

[jw5]

I have read about how the other countries - even the U.K. - consider our GCE O level syllabus and teaching to be excellent. Many countries seem to have copied our syllabuses.

I have just started to give physics revision to my grandnephew in GCE O level physics and I found this (highlighted):
1) definition: The electromotive force, or emf, of an electrical energy source is the work done by the source in driving a unit charge around a complete circuit.
2) potential difference: The potential difference across a component in an electric circuit is the work done to drive a unit charge through the component.

The above two definitions are simply wrong! emf and potential difference are measured in volts (V), energy is measured in joules (J). The proper explanation should be:"There is work done(W) in moving one unit of charge(Q) through a potential difference(V) in an electrical circuit. The formula is W = V x Q".

Actually, the concept of emf/potential difference is not a trivial concept to explained. As an example, it is said that for every meter difference in height in our atmosphere near the ground, the voltage difference may be 120 volts, yet none of us ever get electrocuted.

quote:"The atmospheric potential gradient leads to an ion flow from the positively charged atmosphere to the negatively charged earth surface. Over a flat field on a day with clear skies, the atmospheric potential gradient is approximately 120 V/m."

So I don't know how to explain to my grandnephew. He has to regurgitate the above wrongs if he is not to be penalized!

Our MOE may like to teach advanced concepts early to our students, but doing it correctly can sometimes be tricky.

And "Discover Physics" is written by a Ph.D. !

"Einstein's E=mc² Is Invalid"
Chan Rasjid Kah Chew,
Singapore.
http://www.emc2fails.com

Physics is only useful for engineers and scientists.

 

[ChanRasjid]

Physics is only useful for engineers and scientists.

No Dear! Not at all. Physics is relevant even before the proverbial apple collided with Newton's head.

I belong to the 1980's! The current world is 4 decades ahead of my time according to Einstein's time dilation... whatever! I never have had a mobile phone, but do wear briefs made from cotton harvested from sheep!

Have your heard of "pressure cooker"? Of course! Have I heard of a pressure cooker? Yes,of course! But I only learned about how it actually work about a year ago. We have one at home but seldom in used. Once, I found something cooking and I wanted to open it to see what's inside. It cannot be opened. Then I tried turning the handle, but it won't move. Immediately, I suspected the name of the pot must be "pressure cooker". I stopped meddling(I always have a fear of pressure cooker).

In the afternoon some month's later, our Indonesian maid woke me up to asked for medication. She spoke in Indonesian-Malay about hot water scalding her...missed her face, but got her neck, shoulder, etc. I understood that it was the pressure cooker. I immediately phone the others to come back to take her to the clinic. Luckily she got 3rd degree burns - but why the doctor said not serious!

I later asked "Who taught you how to use the pressure cooker? She said "Nobody" She said she watched Madam (my sister) and therefore tried to use it. I said OMG! You see, the Indonesian education system is all about Islamic knowledge and very little "real material" knowledge. I doubt she knows much about gas pressure, boiling point,..., time dilation, entropy, etc. But all sammsters here - besides memorizing knn, CAQ,...Huat Ah - probably won't be that dumb to force open a pressure cooker!

Physics is about our immediate environment. It is physics that tells us never to attempt to fly jumping down a ten stories building with an open umbrella!

"Einstein's E=mc² Is Invalid"
Chan Rasjid Kah Chew,
Singapore,
http://www.emc2fails.com

 

[JohnTan]

No Dear! Not at all. Physics is relevant even before the proverbial apple collided with Newton's head.

I belong to the 1980's! The current world is 4 decades ahead of my time according to Einstein's time dilation... whatever! I never have had a mobile phone, but do wear briefs made from cotton harvested from sheep!

Have your heard of "pressure cooker"? Of course! Have I heard of a pressure cooker? Yes,of course! But I only learned about how it actually work about a year ago. We have one at home but seldom in used. Once, I found something cooking and I wanted to open it to see what's inside. It cannot be opened. Then I tried turning the handle, but it won't move. Immediately, I suspected the name of the pot must be "pressure cooker". I stopped meddling(I always have a fear of pressure cooker).

In the afternoon some month's later, our Indonesian maid woke me up to asked for medication. She spoke in Indonesian-Malay about hot water scalding her...missed her face, but got her neck, shoulder, etc. I understood that it was the pressure cooker. I immediately phone the others to come back to take her to the clinic. Luckily she got 3rd degree burns - but why the doctor said not serious!

I later asked "Who taught you how to use the pressure cooker? She said "Nobody" She said she watched Madam (my sister) and therefore tried to use it. I said OMG! You see, the Indonesian education system is all about Islamic knowledge and very little "real material" knowledge. I doubt she knows much about gas pressure, boiling point,..., time dilation, entropy, etc. But all sammsters here - besides memorizing knn, CAQ,...Huat Ah - probably won't be that dumb to force open a pressure cooker!

Physics is about our immediate environment. It is physics that tells us never to attempt to fly jumping down a ten stories building with an open umbrella!

"Einstein's E=mc² Is Invalid"
Chan Rasjid Kah Chew,
Singapore,
http://www.emc2fails.com

I'm surprised you didn't train your serf on how to use common household items like the pressure cooker. Did you train her how to boil water too?