SPM Questions: EMF & Internal Resistance

1. The electromotive force and internal
   resistance of the dry cell in the
   circuit
   below is 1.5 V and 0.5 ohm respectively.
   

What is the reading of the voltmeter when the switch is closed? (SPM04)
A. 0V
B. 1.5V
C. Less than 1.5 V
D. More than 1.5 V

Ans: C
E = V + Ir
1.5 = V + I(0.5) , then rearrange he equation,
V= 1.5 – 0.5(I)
Thus V is less than 1.5V

2. Which circuit can be used to determine the electromotive force of a battery? (SPM
   05)

Ans: C , If the switch is opened, the voltmeter across battery will give the e.m.f reading

Physics SPM09: Discussion on e.m.f

After watching the video at least u shud already have the general idea of what e.m.f is all about. Now its time to go in detail according to our SPM syllabus

Under this subtopic,u must be able to

1.Define what is emf?? U can check yr txt book or reference book for the definition..

E.m.f= total energy supplied by a cell(battery)to move a unit of electrical charge through a complete circuit

2. Then one of the most important part, u must be able to differentiate between Potential Difference(voltage) and EMF…U must include the similarities & differences between the two..

I advise u guys to do a table comparison,

3. U must also b able to Explain internal resistance..If u took chemistry, its easier to understand the following explaination…
a battery, has an electrode & electrolyte( i.e the liquid) which are resistive in nature. Due to this it produces internal resistance.

4. and one of the most crucial part is to understand the experiment on how to determine e.m.f & internal resistance
…u’ve got to hafal the circuit diagram..pls refer yr txt / reference book
please read the whole experiment, then analyse the graph.
Your basic maths on straight line must be tip top..otherwise u’ll b having problem to determine emf (E) & internal resistance (r) from the graph of voltage vs current.

Basically the graph is based on this equation:
E=V + Ir ,

re arranging the equation u’ll get
V = - r I + E , Then compare it with

y = m x + c (recall a straight line equation in your maths)

OBSERVE THIS COMPARISON:
axis y = V
gradient, m = - r ( internal resistance)
axis x = I
y-intercept, c = E ( emf)

SPM09: E.M.F & Internal Resistance

Hi there, is time to know more about e.m.f. and internal resistance
Watch this video!..i'll post some questions & discussion soon

SPM Questions: Series & Parallel

Dear all,

..as for today i want to discuss passed SPM questions on series & parallel circuit. At the moment, I'll onlly discuss paper 1 questions.If u look carefully at the trend, most of the questions tried to test your students analystical skill..its not a direct maths calculations of current,voltage or resistance...

Now lets analyse the following SPM questions....

SPM 2004:

1. All the bulbs in the circuit below are identical?

Which of the following statements is true?

A Reading A1 >A2 >A3

B Reading A1 >A3 >A2 Answer: B

C Reading A2>A1>A3

D Reading A3 >A1 >A2

Explaination:
A1 is the biggest coz the current comes out directly from battery. Then this current will be divided into A2 & A3. Seems the bulbs are identical, so resistance at A2 is higher coz the branch is having 2 bulbs in a row. Flow of current will choose a route with smaller resistance, thus current in A3 is bigger.

2. The diagram shows a circuit containing four bulbs, A, B, C and D, which are lit at normal brightness. When a bulb is faulty, no current will flow through it. Which bulb, when faulty will cause all the other bulbs not to light up?

Ans: D

Explanation :Bulb A&C are parallel with B. If B blown up, current stil can flow thru A & C. If either A or C blown up, currrent can flow via B & D.

However, if D blown up, the circuit is open ( or its like jambatan runtuh) i.e no current can flow to negative terminal. Thus all light bulb will not light up.

3. The bulb in the circuit is lit at normal brightness when switches S1 and S2 are

closed.

Ans: A

If only S1 is closed, current will avoid higher resistance R, and follow the path with lower reistance through S1. So larger current will cross the bulb, thus the brightness will increase

If only S2 is closed, current has no choice, it still has to pass through the resistance R, amount of current will drop,thus brightness will decrease.

SPM:Analysing Series & Parallel Circuit

Sorry for not updating frequently last week ..i’ve been focusing on my tuition class..
one thing I can concluded, most of the student can now feel the SPM pressure
Hmm...cuti dah abis...so lets get back to business…

As promised, I’ll b discussing on analysing series & parallel circuit.
Hopefully u'v watched the previous video

2.3 Analysing Series & Parallel Circuit

In this subtopic u need to identify the differences between series & parallel circuit.

The differences are in terms of

i. amount of current passing through in each resistor
ii. voltage across each resistor
iii. and its total resistance

Ok, lets analyse series circuit..

In series circuit, current flows are equal through out the circuit.
I = I1 = I2

But, for voltage,

V=V1 + V2…

and for the total resistance in the bulb equals to,

R= R1 +R2 +R3

in series circuit… if one of the bulb blown up, the other bulb will
not light up.

Lets now examine parallel circuit..
What are the differences in Parallel Circuit compared to series circuit??

1. The arrangement looks different,usually parallel circuit has branches.

2. The amount of current passing through each bulb(resistor) are not equal
if each bulb has different resistance.

3. In terms of calculation,
The amount of current in the circuit can be represented by,
I= I1 + I2

The voltage across the bulb/resistor are equals to the voltage of the battery
V= V1 = V2

and the total resitance of the bulb can be calculated as,
1/R = 1/R1 + 1/R2

4. However, if one of the bulb has blown up, the others are still working

I'll discuss on passed SPM question on next post

SPM Physics Notes: Electricity

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SPM: Series & Parallel Circuit

I will discuss or may b post some questions on this subtopic soon...meanwhile y dont u watch this video & then look at your reference book.. cuti.. cuti jugak!!..tapi jgn langsung tak study :)!!

>

SPM 2008 Results ..

Sorry coz didnt update this site for a while..its a holiday season,i need to take a break :)

Guess what, SPM result has came out..congratulations to my home-tuition student who managed to get an A for their physics like Diana, Kamini, Farhan,Faiz, Siew,Ashraf, Fiqri
..& not too forget for those who got B's..dont be too frustrated coz u've tried your best & i'm proud of u guys. My appreciation also goes to those who never passed their physics b4 & managed to getB or credit this time . I'm also gratefull that none of my student failed their physics.

Overall physics results in Selangor has dropped..not sure about Wilayah..i heard this time the 'A' graph may be higher..but the passing mark a bit lower. My advice to those who dint get an outstanding result, dont be too sad..coz there's always a new opprtunities out there to be grabbed. Life is not only about getting A's,and gettin straight A's wont guarantee that u'll be a succesfull person in near future.
Succes in life is a continuous personal development. It doesn’t matter whether you will end up a prime minister,a millionaire,an engineer,an accountant or a housewife, what matter is how you get there. And along this journey, some mistakes are bound to happen. If you want to make things happen in future,the ability to motivate yourself is a crucial skill. U can only achive this if u know how to learn from mistake, think positively and have a good faith in yourself and GOD.
I wish u all the best in your future.

Anyway..for those who taking SPM this year, be prepared..i think kementerian will give u a tough time to get "A's".. So take the challenge, plan your study and i beg u.. please, & please & please do not wait till last minute,... coz u're not Einstein :)

I left u guys especially SPM 2009 candidate with this news articles.. IF anak nelayan can do it..how about u guys???

Read this..

Tuah Anak Nelayan 1:
Kejayaan pelajar cemerlang negara SPM 2008, Nik Nor Madihah Nik Mohamad Kamal, 18 dari Maahad Muhammadi Perempuan turut dikongsi bersama kerajaan negeri...more

Tuah Anak Nelayan 2:
Bagi pelajar cemerlang Sijil Pelajaran Malaysia 2008, Lim Shu Yong dan Tan Chin Huat dari Sekolah Menengah Jenis Kebangsaan Yoke Kuan, Sekinchan dekat sini usaha sepakat mereka mengulangkaji bersama berjaya menghasilkan 16 A1.
Selain teknik mengulangkaji pelajaran secara berkumpulan, Lim anak seorang nelayan dan Tan, anak seorang tukang besi, mengakui mereka juga memberikan tumpuan sepenuh perhatian di dalam kelas dalam usaha mencapai keputusan cemerlang ini...more

Salam Maulidur Rasul

Our beloved Prophet offers humanity a perfect example in all facets of life. The Holy Quran declares: "Verily, you have in the messenger of Allah, a most beautiful model (Uswa al-Hassanah)." Laqad kana lakum fee rasooli Allahi oswatun hasanatun Quran 33:21

Prophet Muhammad lived among his people and taught them about the belief in one God, ethics in everyday life and the importance of education in leading an exemplary life. In this regard, some of his famous sayings are "Seek knowledge even unto China",

To all muslim, i wish u salam maulidurrasul & have a nice holiday. Hopefully we'll be given the strength by Allah to make Rasullullah as our role model.

As for my muslim SPM candidate, banyakkan selawat sebelum ulangkaji, inshaallah mudah-mudahan anda akan lebih mudah memahami apa yg dipelajari.

SPM Questions: Section 2.1, Electricity

Section 2.1 : Analysing Electric fields & charge flows

1. Which graph shows the relationship between potential difference, V, and current, I, for a resistor that obeys Ohm’s law? (SPM03)

ans: A - Ohm's law will give a straight line graph

2. Which diagram shows the correct electric field pattern?(SPM03)

ans:B, lines of field shall move out from +ve charge.

3. Which circuit can be used to determine the resistance of a bulb? (SPM03)

ans: C, voltmeter should be connected in parallel across the bulb, Ammeter must be connected in series

4.The electric current supplied by a battery in a digital watch is 3.0 x 10 A.

What is the quantity of charge that flows in 2 hours? (SPM04)

A 2.5x107C
B 1.5x105C
C 6.OxlO5C
D 3.6x103C
E 2.2x10’C

ans: E, Q=I x t , t= 2 x60 =120s, then use the value of current & substitute it in the formula.

Download these questions.Click here

Protest & Demonstration against PPSMI

Gerakan aktivis bahasa menentang dasar Pengajaran dan Pembelajaran Sains dan Matematik dalam Bahasa Inggeris (PPSMI) mencipta sejarah apabila turun ke jalan raya, mengulangi peristiwa perarakan Keranda 152 beberapa dekad lalu.

Peristiwa bersejarah pada 3 Mac 1967 itu bagi membantah Rang Undang-undang Bahasa Kebangsaan di Dewan Bahasa dan Pustaka (DBP), waktu itu antara lokasi penting kegiatan sasterawan dan intelektual Melayu.



Mereka merancang mengadakan bantahan ke Parlimen. Nombor '152' merujuk Perkara 152 Perlembagaan Persekutuan yang menyentuh fasal Bahasa Melayu sebagai bahasa kebangsaan Malaysia.

Hari ini, selepas 42 tahun peristiwa penting dalam perjuangan mendaulatkan Bahasa Melayu, kira-kira 8,000 orang berarak dari Masjid Negara selepas jam 2 petang tadi.

Mereka bagaimanapun dihujani tembakan gas pemedih mata oleh polis di sekitar Kampung Attap, hanya beberapa ratus meter dari pintu masuk utama Istana Negara.

Peserta perhimpunan itu - yang asalnya hanya dibenarkan oleh polis diadakan di masjid tersebut - melanggar arahan polis yang melarang sebarang perarakan.

Mereka berhasrat membawa memorandum kepada Yang di-Pertuan Agong bagi memohon campur tangan baginda dalam pemansuhan dasar kontroversi itu yang diperkenalkan sejak 2003.

Polis pada mulanya berkawal dekat mahkamah syariah Wilayah Persekutuan, beberapa ratus meter dari Masjid Negara, jalan menuju istana melalui Lebuhraya Mahameru.

Untuk memintas sekatan polis di situ, kumpulan ribuan penentang dasar tersebut - termasuk pemimpin dan penyokong PAS dan PKR - bergerak melalui jejantas depan masjid menuju ke arah Kampung Attap melalui Jalan Syed Putra.

Polis melepaskan berpuluh-puluh das gas pemedih mata ke arah kumpulan penentang dasar PPSMI di situ bermula jam 2.40 petang sehingga memecahkan kumpulan tersebut kepada beberapa kelompok kecil.

Suasana kelam-kabut, orang ramai yang berpakaian putih dengan tulisan merah "Mansuhkan PPSMI" dan "Selamatkan Bahasa Melayu" - sebagai lambang membantah PPSMI - di barisan hadapan bertempiaran lari.

Walaupun kelihatan asap gas pemedih mata berkepul-kepul di udara, barisan belakang peserta perhimpunan terus bergerak ke depan, dengan harapan dapat menuju ke Istana Negara.

Mereka bersurai seketika bagi mengelak kesan asap gas pemedih mata. Manakala sebahagian lagi terus berdegil cuba berarak ke istana walaupun diminta bergerak pulang ke masjid.

Polis antirusuhan pula memancutkan air kepada orang ramai di jalan pendek menuju mahkamah syariah dari arah Jalan Syed Putra sewaktu mereka ingin pulang ke lokasi awal perhimpunan.

Sebahagian peserta demonstrasi telah kembali ke Masjid Negara selepas jam 3 petang tadi.

Ratusan orang ramai yang berkumpul di perkarangan masjid sekali lagi ditembak dengan gas pemedih mata. Beberapa das tembakan kedengaran.

Sementara di Istana Negara, kawalan lebih 150 anggota polis dan unit pencegah rusuhan FRU, termasuk kenderaan pemancut air.

Polis membuka semula laluan hampir jam 4 petang di Lebuhraya Mahameru dari kedua-dua arah yang ditutup selama 90 minit bagi menghadapi sebarang kemungkinan.

Empat lelaki berusia, dijangka antara 30-an hingga 50-an, ditahan polis dan mereka dimasukkan di dalam sebuah trak di depan istana.

Butiran lanjut belum diperolehi. Usaha Malaysiakini mendapatkan ulasan pegawai polis di situ gagal.

Penasihat Gabungan Mansuhkan PPSMI (GMP), yang menganjurkan perhimpunan itu, Sasterawan Negara Datuk A Samad Said dan pengerusinya Datuk Dr Hassan Ahmad berjaya menyerahkan memorandum anti-PPSMI jam 2.50 petang.

Penolong Datuk Paduka Maharajalela, Azuan Effendy Zairakithnaini menerima memorandum bersejarah itu di pintu masuk utama Istana Negara kira-kira jam 2.50 petang.

Lima lagi pemimpin GMP yang dijadual menyerahkan memorandum tersebut tidak kelihatan, dipercayai tersekat dalam kumpulan penyokong gerakan itu.

Bercakap kepada media selepas penyerahan, A Samad berkata rombongan pemimpin GMP pada asalnya merancang ke istana dengan kereta, bagaimanapun ia gagal kerana kesesakan.

"Saya berjalan, sepatutnya diiringi dengan motokar," katanya.

Tambahnya, inilah "pengalaman pertama" matanya pedih dan mengalami keadaan tolak-menolak dalam kumpulan penentang PPSMI sewaktu menuju ke istana.

"Rupa-rupanya begini caranya untuk menyelamatkan bahasa," katanya (dua dari kanan).

Perjuangan menentang dasar ini tidak akan berhenti hari ini, malah ia akan diteruskan pada masa akan datang, katanya lagi.

Selain Ketua I Persatuan Penulis Nasional (Pena) Datuk Baha Zain dan beberapa sasterawan Melayu, pemimpin pembangkang yang kelihatan termasuk Presiden PAS Datuk Seri Abdul Hadi Awang, timbalannya Nasharuddin Mat Isa, naib presiden Mohamad Sabu, setiausaha agung Datuk Kamaruddin Jaafar, ketua penerangan Datuk Mahfuz Omar dan naib ketua Angkatan Muda PKR Khairul Anuar Ahmad Zainuddin.

SPM 2008 Results on 12 March

KUALA LUMPUR: Keputusan peperiksaan Sijil Pelajaran Malaysia (SPM) dan Sijil Tinggi Agama Malaysia (STAM) 2008 akan diumumkan pada 12 Mac ini.

Ketua Pengarah Pelajaran, Datuk Alimuddin Mohd Dom, dalam kenyataan hari ini berkata calon yang menduduki kedua-dua peperiksaan itu boleh mendapatkan keputusan mereka di sekolah masing-masing bermula jam 10 pagi.

"Calon persendirian pula akan mendapat keputusan mereka melalui pos yang akan dihantar oleh Jabatan Pelajaran Negeri," katanya.

Alimuddin berkata, pengumuman analisis keputusan SPM dan STAM 2008 akan diadakan serentak pada 12 Mac jam 9 pagi di Putrajaya.

Seramai 442,936 orang calon telah mendaftar untuk menduduki peperiksaanSPM 2008 dan daripada jumlah itu 388,079 atau 87.6 peratus adalah calon sekolah Kementerian Pelajaran, 16,019 (3.6 peratus) calon sekolah kerajaan negeri dan tajaan badan-badan tertentu, 10,331 (2.3 peratus) calon sekolah swasta dan 28,507 (6.5 peratus) calon persendirian perseorangan, katanya. - Bernama

SPM Physics 09 Note: Topic 2.1

Hi ..i've got this note thru a friend & wanna share it with u guys..u need to dwnload the file to know the answer in the blank space.

Factors Affecting Resistance

In this post, i wanna discus the next section 2.2 learning outcome which is:

1. Factors that affect resistance. What are the factors???

i. Length(l) of conductor :
R is directly proportional with l. The longer the length the bigger the resistance.

Just imagine if you need to choose between1000m & 5000m marathon, which one will cause bigger resistance to you?

ii. Area(crossectional area,A) of conductor:
R is inversely proportional with A i.e the bigger the area the smaller the resistance

iii. Temperature(T):
R is directly proportional with T
The higher the temperature, the bigger the resistance.

iv. Type of conductor
Resistance depends on type of conductor used, different metals have differen resistive value.
Silver has less resistance than copper..but usually copper is widely used in a lab coz its cheaper.

Please check out the experiment involved on factors affecting resistance in yr text/reference book.

2.The next outcome, u must be able to-
Describe superconductors:
Superconductors are materials that have almost ZERO resistance as the temperature
decrease towards absolute zero (-273 degree celcius).

Superconductors can carry current without loss of energy..thus the transfer of energy is very efficient.

Its application is widely used in levitated train (bullet train).