electricity can you fill in the symbols for the circuit components using page 176 and 181
TRANSCRIPT
![Page 1: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/1.jpg)
ElectricityCan you fill in the symbols for the
circuit components using page 176 and
181
![Page 2: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/2.jpg)
Today’s lesson
• Electrical symbols
• Charge
• Series and Parallel circuits
• Understand that current is the rate of flow of charge
• Recall and use: Q = It
• Looking at current in different circuits
• Conventional current
![Page 3: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/3.jpg)
☺☺
☺
☺
☺☺☺
☺
☺
☺
☺
![Page 4: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/4.jpg)
☺☺
☺
☺
☺☺☺
☺
☺
☺
☺
cell
energy
electron
lamp
![Page 5: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/5.jpg)
☺☺
☺
☺
☺☺☺
☺
☺
☺
☺
cell
energy
electron
lamp
Can you copy this please?
![Page 6: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/6.jpg)
Electrons
☺
Hi, I’m Eleanor the electron.
![Page 7: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/7.jpg)
Coulomb of charge (electrons)
Think of it as a “bag of electrons” (containing 6000000000000000000 electrons!)
☺ ☺☺
☺ ☺
☺☺
☺ ☺
☺☺
☺ ☺
☺☺
☺☺
☺☺☺☺ ☺
☺
☺ ☺
☺
☺ ☺☺
☺ ☺
☺☺
☺☺
☺☺☺
![Page 8: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/8.jpg)
Current
The number of Coulombs flowing past a point in the circuit every second.
I = Q/t
☺☺
☺
☺
☺☺☺
☺
☺
☺
☺
A
I’m counting how many
coulombs of electrons go
past me every second
1 Amp = 1 coulomb per second
![Page 9: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/9.jpg)
Current
The number of Coulombs flowing past a point in the circuit every second.
I = Q/t
☺☺
☺
☺
☺☺☺
☺
☺
☺
☺
A
I’m counting how many
coulombs of electrons go
past me every second
1 Amp = 1 coulomb per secondCan you copy this please?
![Page 10: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/10.jpg)
☺
Let’s build some circuits!
Do experiments 31.4 to 31.10 page 256-
257
![Page 11: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/11.jpg)
In a series circuit
Current is the same at any point in the circuit
2.5 A
2.5 A 2.5 A
2.5 A
![Page 12: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/12.jpg)
In a series circuit
Current is the same at any point in the circuit
2.5 A
2.5 A 2.5 A
2.5 A
☺Can you copy this please?
![Page 13: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/13.jpg)
Today’s lesson
• Looking at current in different circuits
• Recall and use: Q = It
• Understand that voltage is the number of joules per coulomb transferred
• Looking at voltage in different circuits
![Page 14: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/14.jpg)
In a parallel circuit
The current splits (total current stays the same)
2.5 A
2.5 A
1.25 A
1.25 A
![Page 15: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/15.jpg)
In a parallel circuit
The current splits (total current stays the same)
2.5 A
2.5 A
1.25 A
1.25 A
☺Can you copy this please?
![Page 16: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/16.jpg)
Milliamps!
1 A = 1000 mA
1 mA = ?
![Page 17: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/17.jpg)
Milliamps!
1 A = 1000 mA
1 mA = 0.001 A
![Page 18: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/18.jpg)
Stand up!
![Page 19: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/19.jpg)
Voltage(emf)☺
☺☺
☺
☺☺☺
☺
☺
☺
☺V
I’m checking the difference in energy (per
coulomb) between the 2 red arrows
1 Volt = 1 Joule per coulomb
![Page 20: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/20.jpg)
Voltage (p.d.)☺
☺☺
☺
☺☺☺
☺
☺
☺
☺
V
I’m checking the difference in energy (per
coulomb) before and after the lamp
1 Volt = 1 Joule per coulomb
![Page 21: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/21.jpg)
Voltage
Voltage is the amount of energy transferred (changed) per coulomb of charge.
![Page 22: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/22.jpg)
Let’s build some
circuits!
☺
![Page 23: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/23.jpg)
Stand up!
![Page 24: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/24.jpg)
In a series circuitThe sum of the voltages across the lamps
equals the voltage across the cells
9 V
3 V 3 V 3 V
![Page 25: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/25.jpg)
In a series circuitThe sum of the voltages across the lamps
equals the voltage across the cells
9 V
3 V 3 V 3 V
☺Can you copy this please?
![Page 26: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/26.jpg)
Stand up!
![Page 27: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/27.jpg)
In a parallel circuitIn a simple parallel circuit, voltage across each lamp equals the voltage across the cells
5 V
5 V
5 V
![Page 28: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/28.jpg)
In a parallel circuitIn a simple parallel circuit, voltage across each lamp equals the voltage across the cells
5 V
5 V
5 V
☺Can you copy this please?
![Page 29: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/29.jpg)
Today’s lesson
• Understand the term resistance
• Recall and use: V =IR
![Page 30: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/30.jpg)
Stand up!
![Page 31: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/31.jpg)
Resistance
Measures how difficult it is for current to flow. Measured in Ohms (Ω)
VA
Resistance = voltage/current R = V/I
![Page 32: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/32.jpg)
Resistance
Measures how difficult it is for current to flow. Measured in Ohms (Ω)
Resistance = voltage/current R = V/I
☺Can you copy this please?
![Page 33: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/33.jpg)
Ohm’s Law
• V = IR
V
RI X
![Page 34: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/34.jpg)
Let’s measure a resistance!
![Page 35: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/35.jpg)
Resistance of a lamp
AV
Resistance = voltage/current R = V/I
Vary the voltage and current using a variable resistor (rheostat). Plot a graph of resistance against current
![Page 36: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/36.jpg)
Resistance of a lamp
V(V) I(A) R(Ω)
I(A)
R(Ω)
![Page 37: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/37.jpg)
Homework!
Read pages 176 and 177Answer questions on page 177Due Wednesday 25th November
![Page 38: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/38.jpg)
Resistance of a lamp
• As the current in a lamp increases, it gets hotter, and its resistance increases. Why?
![Page 39: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/39.jpg)
Resistance of a lamp
• As the current in a lamp increases, it gets hotter, and its resistance increases.
Copy please.
![Page 40: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/40.jpg)
Let’s try some resistance questions
![Page 41: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/41.jpg)
Today’s lesson
• Understand the term power
• Recall and use: P =VI
• Recall and use E = VIt
![Page 42: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/42.jpg)
Power
The amount of energy used by a device per second, measured in Watts (Joules per second)
VA
Power = voltage x current P = VI
![Page 43: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/43.jpg)
Power
The amount of energy used by a device per second, measured in Watts (Joules per second)
VA
Power = voltage x current P = VI
☺Can you copy this please?
![Page 44: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/44.jpg)
Power of a lamp
AV
Power = voltage x current P = VI
Measure the power of the lamp at it’s operating voltage. What is the electrical energy being turned into?
![Page 45: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/45.jpg)
Example
• A 200 W television is plugged into the 110V mains. What is the current in the television?
PIV X
![Page 46: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/46.jpg)
Example
• A 200 W television is plugged into the 110V mains. What is the current in the television?
• I = P/V = 200/110 = 1.8A
PIV X
![Page 47: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/47.jpg)
Example
• A kettle uses 240V and 8A. What is its power?
PIV X
![Page 48: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/48.jpg)
Example
• A kettle uses 240V and 8A. What is its power?
• P = VI = 240x8 = 1920W (=1.9kW)
PIV X
![Page 49: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/49.jpg)
Remember
Power is the amount of energy used by a device per second, measured in Watts (Joules per second)
VA
Power = voltage x current P = VI
![Page 50: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/50.jpg)
Total energy
So the total energy transformed by a lamp is the power (J/s) times the time the lamp is on for in seconds,
E = VItE = energy transformed (J)
V = Voltage (also called p.d.)
I = current (A)
t = time (s)
![Page 51: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/51.jpg)
Example
• A kettle uses 240V and 8A. What is its power?
• P = VI = 240x8 = 1920W (=1.9kW)
• How much energy does the kettle use in 5 minutes?
PIV X
![Page 52: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/52.jpg)
Example
• A kettle uses 240V and 8A. What is its power?
• P = VI = 240x8 = 1920W (=1.9kW)
• How much energy does the kettle use in 5 minutes?
• E = VIt = 240x8x300 = 576000 J PIV X
![Page 54: Electricity Can you fill in the symbols for the circuit components using page 176 and 181](https://reader034.vdocuments.us/reader034/viewer/2022051819/55140c69550346d8488b4e56/html5/thumbnails/54.jpg)
Let’s try some questions!