Advanced Electric Circuit

Advanced Electric Circuit

"Because resist doesn't mean stop"

PHET Simulation

https://phet.colorado.edu/sims/html/circuit-construction-kit-dc/latest/circuit-construction-kit-dc_en.html

Observe your circuit

• The relation between the movement of charge and the value of electric current.

• The effect when the resistance of the lamp is increasing or decreasing

• Direction of electron and conventional current

Multiple Choice

Which one is the direction of electron?

• From positive to negative

• From negative to positive

Multiple Choice

Which one is the direction of conventional current?

• From positive to negative

• From negative to positive

Multiple Choice

What is the relation between electron movement speed and electric current?

• The larger the current, the electron will moves faster

• The larger the current, the electron will moves slower

• There is no relation

Multiple Select

When you decrease the resistance of lamp and resistor to 0 ohm, what happen with the circuit?

• The electric current really large

• The battery is on fire (explode)

Multiple Select

What happen when you increase the resistance of the lamp?

• Electric current decreases

• Electric current increases

Electric current

 $I=\frac{Q}{t}$  
Where
I = electric current (A)
Q = electric charge (C)
t = time (s)

Multiple Choice

If 12.5 x 10¹⁸ electrons move through a lamp in 3.2 seconds, what current is flowing through the lamp? (electron charge = -1.6 x 10^-19 C)?

• 0.625 A

• 2 A

• 0.5 A

Multiple Choice

How many coulombs of charge move through an ammeter in 8 seconds if it is reading 0.95 A?

• 7.6 C

• 3.8 C

Voltage

is a measure of the amount of energy a component transfer per unit of charge passing through it

 $V=\frac{E}{Q}$  
Where
V = voltage (V)
E = energy transferred (J)
Q = charge passing (C) 

Electromotive force (emf) and Potential Difference

• On picture beside, which one is the emf and which one is the potential difference!

• Potential difference is for a component

• Emf is for a supply voltage

• Around the circuit, the total of all emf will be the same as the total off all p.d.

Electrical model

• Gain gpe -> battery give electron electrical energy

• Wherever the track if it start and end at some point, the change in gpe will same --> Parallel, the potential difference is same.

• For every obstacle, there is energy transfer -> electrical component need potential difference

• Can this model explain series circuit?

Multiple Choice

A cell provide 76 C of charge with 120 J of energy. What is the cell's emf?

• 1.58 V

• 3.16 V

Multiple Choice

When a lamp carries a current of 2.4 A for 5.4 s, it transfers 120 J of energy. What is the p.d across the lamp?

• 9.26 V

• 4.63 V

• 2.33 V

Resistance

• Electrical resistance is considered to be the opposition to the flow of current within a conductor

•  $R=\frac{V}{I}$  

• R = resistance

• V = potential difference (V)

• I = electric current (A)

Ohmic Conductor

• Is an electric component that follows Ohm's Law

• Resistance is constant

• Graph between I and V:

• How to find the value of resistance based on this graph?

• So, is there any electric components that don't follow Ohm's Law?

Multiple Choice

Based on I-V graph, how to find the value of resistance?

• Find the gradient of the line

• Find the area under the graph

Filament Bulb

As the temperature of metal inside the filament bulb, what happen with the resistance?

Diode

• Only conducts in the forward direction

Thermistor

• Resistance of thermistor change as the temperature change

• Thermistor don't obey Hooke's Law

• https://www.youtube.com/watch?v=9opuvLXAetI&t=220s

Multiple Choice

What happen with resistance in filament bulb when the temperature of metal increase?

• The resistance of metal increase

• The resistance of metal decrease

• Nothing happen

Conclusion (keyword)

• Electric charge

• Electric current

• Potential difference and electromagnetic force

• Resistance and Ohm's Law

• Filament Bulb

• Diode

• Thermistor

Poll

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