## Thursday, May 28, 2009

### My Physics Short notes

Level 1 questions and short notes for quick review

1. Form 4 chapter 1 Introduction
2. Form 4 chapter 2 Force and motion
3. Form 4 chapter 3 Force and pressure
4. Form 4 chapter 4 Heat
5. Form 4 chapter 5 Light
6. Form 5 chapter 1 Waves
7. Form 5 chapter 2 Electricity
8. Form 5 chapter 3 Electromagnetism
---Transformer
9. Form 5 chapter 4 Electronics
10. Form 5 chapter 5 Radioactivity

### How to answer Physics Papar 2 &3

Guide lines to answer SPM Physics paper 2 and 3.( SPM real paper 2006 )Microsoft Power Point - FIZIK K3 [Compatibility Mode]

FIZIK K2

## Monday, May 25, 2009

### 3.2 THE FORCE ON A CURRENT-CARRYING CONDUCTOR IN A MAGNETIC FIELD

You should able to answer the following questions .

1. Describe whathappens to current-carrying conductor in a magnetic field
• An electric current produces a magnetic field around it.

• When a wire carries an electric current through another magnetic field, a force is exerted on the wire.
• The magnetic force on a current-carrying conductor is in a magnetic field is due to the combination of the magnetic field due to the current in the conductor and the external
magnetic field to produce a resultant magnetic field( or knows as The Catapult Field).

2. How would you determine the direction of the magnetic force acting on the wire?

The direction of the magnetic force, F, acting on the wire can be determined by using Fleming’s left-hand rule.

3. What is Fleming’s Left – Hand Rule ?

If the forefinger, second finger and the thumb of the left hand are extended at right angles to each other, with the forefinger in the direction of the magnetic field, the second finger in the direction of the current, then the thumb will point the direction of the force, F or motion.

4. Explain the factors that affect the magnitude of the force on a current-carrying conductor in a magnetic field.

The magnitude of the force on a current-carrying conductor in a magnetic field depends on:
i. the size of the current in the conductor
ii. the strength of the magnetic field.

5. Describe how a direct current motor works

Commutator: reverse the direction of current in the coil every half rotation so that the coil continues to turn in same direction

Carbon Brush: to contact with the commutator so the current from the battery enters the coil.

Spring: push the brush so it will always contact with the commutator.

The direct current motor (d.c. motor) uses the turning effect on a current-carrying coil in a magnetic field.

when current flows in the coil placed in a magnetic field, a pair of forces which are equal in magnitude but opposite in directions is produced.

The forces act on the opposite segments of the current-carrying coil in a magnet field and provide the turning effects that cause the motor to rotate.

video source : http://web.ncf.ca/ch865

6. How to increase the speed of rotation of the motor.

i. Increasing the size of the current

ii. Increasing the strength of the magnetic field

iii. increasing the number of turns

iv. Increasing the area of the coil

## Saturday, May 23, 2009

### Form 5 Add Math Project 2009

*Edit before handout :D

## Friday, May 22, 2009

### Manga Guide To Physics ...Physics not bored

If you're mystified by the basics of physics or you just need a refresher, The Manga Guide to Physics will get you up to speed in a lively, quirky, and practical way.

The Manga Guide to Physics (Excerpt)

The Manga Guide to Electricity (excerpt)

Please note that you can download this document as a PDF. To fullscreen the Scribd viewer, click the box in the upper righthand corner.

Use discount code 210293031 when ordering direct from nostarch.com for 25% off your order!

(http://www.nostarch.com/mg_physics.htm)

## Wednesday, May 20, 2009

### Form 1 Science notes

My Scribd's Documents:

Click the title below to link on the document.

1. nota padat math f1 Chapter 4 and 5

2. Science form 1 chapter 2
Science Form 1 Chapter 2

3. Science form 1 chapert 3
form 1 science chapter 3 Matter

4. Science form 1 chapter 4
Form 1 Science Chapter 4

5. Science form 1 chapter 6 Energy
F1 c6 Energy

6. Science form 1 chapter 7(a) heat
f1 c7 hear 1

7. Science form 1 chapter 7 (b) heat

f1 c7 heat 2

### Musim Peperiksaan

Sebelum berseronak pada cuti pertengahan tahun,suka tak suka murid-murid juga terpaksa merasai kepahitan Peperiksan Pertengahan Tahun pada hujung bulan May ini.

Dibawah menunjukkan perbezaan hidup antara murid-murid dengan guru-guru;

sebelum peperiksaan bermula:
murid rajin -- telankan apa-apa saja yang mungkin akan ditanya semasa peperiksaan.
sibuk mengulangkaji dan buat latihan tubi, takut tak dapat high score.
murid sederhana-untuk menyenakkan hati diri sendiri dan ibu bapa, "ulangkaji" di pusat tuisyen.
murid malas-- peperiksaan bila ?

guru-- sibuk mengisi borang JSJ, cari soalan dan menaip soalan .

sewaktu peperiksaan:
murid-- cuba sedaya upaya untuk memberikan jawapan yang paling tepat termasuk meniru.
guru-- mengawasi murid supaya tidak berlaku penyelewangan.

selepas peperiksaan:
murid-- mengejar guru untuk mendapatkan markah.
guru--mengelakkan gangguan murid supaya dapat menyemak kertas jawapan murid.

## Monday, May 18, 2009

Form 4 Chapter 3
Force and Pressure

3.1 Understand Pressure

You should be able to

1. Conceptulise pressure as force over area.

2. solve quantitative problems involving pressure.

3. describe applications of pressure.

Common questions:

1. What is the relationship between the pressure and surface area?

The smaller the surface area, the bigger the pressure.

2. What is the relationship between the force and the pressure?

The bigger the force, the bigger the pressure.

3. What is the SI unit for pressure?

Nm-2 or Pascal (Pa).

4. The applications of pressure in daily life. Examples :

The blade of a knife has a very small area that exerts such a high pressure that the meat can be cut easily.

The sharp tip of a thumbtack has a very small area in contact with the board. Hence the tip can pierce through the board due to the high pressure it exerts.

You will not sink into the snow if you are wearing skis. The pressure exerted is low due to the large surface area of the skis.

The large tracks of a bulldozer help to reduce pressure so that the heavy bulldozer will not sink into the soft ground.

Simple calculations:

1. The diagram below shows the dimension and the weight of a wooden block resting on the floor.

Calculate

(i) the maximum pressure exerted, and

(ii) the minimum pressure exerted.

2. A student is pressing a thumbtack into a notice board with a force of 15 N. The area of the head and the tip of the thumbtack is 0.0001 m2 and 1×10-6 m2 respectively.

(i) Calculate the pressure exerted on the student’s thumb.

(ii) Calculate the pressure exerted by the thumbtack onto the notice board.

(iii) What causes the difference in pressures calculated in 2(i) and 2(ii)?

3. A four legged table of 200 N has a total cross sectional area of 40 cm2. What is the average pressure exerted by each leg of the table to the floor?