Physics F5C5 transistors

1)Amplifier
•The function of microphone: convert sound energy to electric energy
• The function of loud speaker: convert electric energy to sound energy
- When a person speaks through a microphone, the sound waves are converted into an alternating current
- A small change in base current will cause a big change in the collector current
- The loudspeaker thus receives a large alternating current from the collector current and converts it into loud sound.
- The capacitor blocks a steady current (direct current) from flowing into the transistor and microphone

2)Light controlled switch
- At night, the light dependent resistor resistance is very high compared to resistor R
- Base voltage increase > Vbe
- Base current increase
- High enough to switch on the transistor
- The bulb light up

• What if you want the bulb to light up in the morning?
Ans: interchange the position btwn LDR and resistor R

3) Fire Alarm Automatic Switch
- When the thermistor increase, it has smaller resistance
- Thus, the voltage across the resistor R increases and becomes very high
- Base current increases
- Collector current increases
- The bulb light up

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Physics F4C4 Frequent Asked Questions

Why is mercury used in thermometer ?
- Expand uniformly
- Opaque
- Doesn't stick to the glass wall

What is the function of constriction in thermometer?
- to avoid mercury returns back to the bulb
• When we took out the thermometer from the mouth, the temperature will drop
• With constriction, the temperature won't drop.
• Thus, we can read the temperature easily

What are the characteristics of a good thermometer?
1) have thin capillary tube
- increase sensitivity
2) thin wall of bulb
- absorb heat faster
3) small size of bulb
- absorb heat faster

#physics #f4
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Physics F4C4

Working principle of car radiator system
- combustion of fuel in the engine produces a lot of heat
- the pump forces the water to pass through the hot engine block areas and the water absorb heat
- the specific heat capacity of water is high
- it absorbs a lot of hear
- hot water flows to the radiator and is cooled through a cooling fin.

#physics #f4
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Physics F4C4 essay

Modifications of grill
i) outer coating on grill body : ceramic / porcelain
- high specific heat capacity
ii) additional tool on the grill 1 : lid
- reduce heat loss
iii) additional tool on the grill 2 : fan
- supply more oxygen

#physics #f4
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Physics F5C2 Archimedes' Principle

Essay related to Hydrometer

Thin and long stem
- bigger range of liquid density
Made of glass
- not easy to erode
Large bulb
- greater buoyant force
High density of lead granules
- ensure the hydrometer always upright

#physics #f5
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💡Physics with Heera

📡Chapter 3 : Electricity

! IMPORTANT DEFINITIONS !
Part 1

🔎E.H.T
👉🏻Extra high tension

🔍Electric field
👉🏻The REGION around a charged particle where any charge in the region will experience an electric force.

🔍Electric field strength, E
👉🏻Electric force acting on a unit postive charge placed at a point.

🔍Current, I
👉🏻The rate of flow of charge, Q in a conductor

🔍Potential difference, V
👉🏻The work done, W in moving one coulumb of charge, Q from one point to another.
V = W/Q or
V = E/Q

🔍Resistance
👉🏻Ratio between potential difference, V and current, I.
R = V/I

🔍Rheostat
👉🏻Control the current flow

🔍s.w.g.
👉🏻Size wire gauge

#physics #c3 #f5
#heera

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💡Physics with Heera

! IMPORTANT DEFINITIONS !
Part 2

🔍Resistivity of a conductor, p
👉🏻Measure of a conductor's ability to oppose the flow of the electric current.

🔍Superconductors
👉🏻Materials that conduct electricity without any resistance.

🔍Critical temperature, Tc
The temperature when the resistivity of a superconductor becomes ZERO.

🔍Electromotive force (e.m.f.)
Energy transferred or work done by an electrical source to move one coulumb of charge in a complete circuit.

🔍Voltage drop
Value of potential difference across the circuit, V is SMALLER than the e.m.f. of the dry cell
V < e.m.f.

🔍Internal resistance, r of dry cell
The resistance caused by electrolytes in the dry cell
🧠Apa effects??
😿Loss of energy in the form of heat in dry cell
😿V < e.m.f. ---- (voltage drop👀)


#physics #c3 #f5
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💡Physics with Heera👩‍🏫

Chapter 1 - Force and Motion II
🌷1.4 Elasticity

Elasticity
👉The property of material that enables an object to return to its original shape and size after the force applied on it is removed

Hooke's Law
👉The extension of spring (x) is directly proportional to the force applied on the spring (F) provided the elastic limit of the spring is not exceeded

k is spring constant

F=kx

#physics #f5 #c1
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🦋*ੈ✩‧₊˚ 『 @serenenotes 』

💡Physics with Heera👩‍🏫

Important Definitions !

🌷Chapter 1 - Force and Motion II

1⃣Weight
👉The gravitational force acting on an object

2⃣Force
👉A push or pull upon an object

3⃣Resultant Force
👉The single force that represents the vector sum of 2 or more forces acting on an object
👉The total force acting on the object

4⃣Free body diagram of an Object
👉Diagram that shows all the forces acting on that object only

5⃣Newton's 2nd Law of Motion (F=ma)
👉The rate of change of momentum is directly proportional to the force
👉Acts in the direction of the applied force

6⃣Acceleration (a= v-u / t)
👉Rate of change of velocity

7⃣Resolution of Forces
👉The process of resolving a force into 2 components
- Vertical and horizontal

8⃣Equilibrium of Forces or (Forces in Equilibrium)
👉The force acting on it produce a zero resultant force

9⃣Elasticity
👉The property of material that enables an object to return to its original shape and size after the force applied on it is removed

🔟Hooke's Law
👉The extension of a spring (x) is directly proportional to the force applied on the spring provided the elastic limit of the spring is not exceeded.

#physics #f5 #c1
#heera

🦋*ੈ✩‧₊˚ 『 @serenenotes 』

💡Physics with Heera👩‍🏫

Chapter 1 - Force and Motion II
🌷1.4 Elasticity

Elasticity
👉The property of material that enables an object to return to its original shape and size after the force applied on it is removed

Hooke's Law
👉The extension of spring (x) is directly proportional to the force applied on the spring (F) provided the elastic limit of the spring is not exceeded

k is spring constant

F=kx

#physics #f5 #c1
#heera

🦋*ੈ✩‧₊˚ 『 @serenenotes 』

💡Physics with Heera

4.1 Force on a Current-carrying Conductor in a Magnetic Field

🧲When a current-carrying conductor is placed in a magnetic field, the conductor will experience FORCE

🧲Direction of the force depends on :
🔋Direction of the current
🔋Direction of the magnetic field

🧲Force on a current-carrying conductor in a magnetic field is produced by?
👉The interaction between 2 magnetic fields
● magnetic field from the electric current in the conductor
●magnetic field from the permanent magnet

🫂The 2 magnetic fields combine to produce resultant magnetic field that is known as CATAPULT FIELD
🍁The PATTERN of the catapult field = direction of the force acting on the conductor

What is Catapult field? (Pg 138)

👉A resultant magnetic field produced by the interaction between the magnetic field from a current-carrying conductor and magnetic field from a permanent magnet

~ to be continued ~
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💡Fizik bersama Heera dan Hanis

4.1 - Daya ke atas konduktor pembawa arus dalam suatu medan magnet

🧲 Apabila konduktor pembawa arus diletakkan dalam suatu medan magnet, konduktor tersebut akan mengalami DAYA

🧲 Arah daya bergantung pada :
🔋 Arah arus
🔋 Arah medan magnet

🧲 Daya pada konduktor pembawa arus dalam medan terhasil daripada ?
👉 Interaksi di antara 2 medan magnet
● medan magnet drpd arus elektrik dalam konduktor
● medan magnet drpd magnet kekal

🫂 - 2 medan magnet ini bergabung utk menghasilkan 1 medan magnet paduan yg dikenali sbgai MEDAN LASTIK

🍁 CORAK medan lastik = arah tindakan daya pada konduktor itu

Apakah itu medan lastik ? (Pg 138)

👉 medan magnet paduan yg dihasilkan oleh interaksi antara medan magnet drpd konduktor pembawa arus dgn medan magnet drpd magnet kekal

~ bersambung ~

🪴English Version : https://t.me/serenenotes/365

#physics #c4 #f5
#malay
#heera

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Frequently asked question in Physics F4C5

How does a turning fork produce sound waves?
- When a turning fork vibrates, layes or air vibrate.
- The particle of air undergoes series of compression & rarefaction
- Sound energy is propagated through the air in the form of waves

#physics #f4
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💡Physics with Heera

Chapter 2 - Pressure😮‍💨
📡2.5 : Archimedes' Principle

🏖Buoyant Force
(PDF)

#physics #c2 #f5
#heera

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Senarai Definisi Fizik

#physics #fizik
#malay
#f4 #f5

🦋*ੈ✩‧₊˚ 『 @serenenotes 』

💡Physics with Heera👩‍🏫

Chapter 1 - Force and Motion II
📡1.1 - Resultant Force

#physics #f5 #c1
#heera

🦋*ੈ✩‧₊˚ 『 @serenenotes 』

💡Physics with Heera👩‍🏫

Chapter 1 - Force and Motion II

📡1.1 - Resultant Force
(PDF)

#physics #f5 #c1
#heera

🦋*ੈ✩‧₊˚ 『 @serenenotes 』

💡Physics with Heera👩‍🏫

Chapter 5 : Waves (F4)
🌈Electromagnetic Waves

Definition !
🌸Made up of magnetic field and electric field that oscillates perpendicularly to one another

👉Mneumonic
Raju Mumbled I Love U eX Girlfriend

Raju - Radiowave
Mumbled - Microwave
I - Infrared
Love - Visible Light
U - Ultraviolet
eX- Xray
Girlfriend - Gamma ray

#physics #f4 #c5
#heera

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