The big question:How can we summarize electricity, current and charge

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Homework: p82, q4Due: ThursShow working

I will not be cross if you didn’t knowwhat to do, I will be cross if you didn’ttry something!

Learning Objective: To combine understanding of current and charge

The big question:How can we summarize electricity, current and charge

A – Predict current time graphs using chargeB – Evaluate current time graphsC – Link speed = distance / time and chargeD – Calculate charge, current or time

How many mistakes?

10-6 x 10-3 = 10-3

A man runs 50x102 metres in 0.5 x 104 seconds, so his speed is 0.1

If charge = current x time, then charge of a 10-1 current in 5 x 10-1

seconds is 5 x 10-2

Set up this circuit

-Measure the current-Measure the distancearound the circuit

If 1 electronmoved at 10ms-1, work out TIME and then CHARGE

Charge, Q = current, I x Time A

1 coulomb = 1 Amp x 1 Second

A 5A current passes how much chargein 0.5 seconds?

2.5A 5C

2.5 C 5A

A 3x20-1 current passes how muchcharge in 10-4 seconds?

3 x 20-1 ÷ 10-4 3 x 201 ÷ 104

3 x 2x 101 x 104 3 x 2x 10-1 x 10-4

Electron speed in wire is 5ms-1

A circuit is 5 metres longA current of 1.6x10-19 A flowsCan you calculate its charge in a second?

Yes No

Learning Objective: To combine understanding of current and charge

The big question:How can we summarize electricity, current and charge

A – Predict current time graphs using chargeB – Evaluate current time graphsC – Link speed = distance / time and chargeD – Calculate charge, current or time

(D) What is the time taken for103 A to give 5x105 C of charge?(C) Electron speed in a copperwire is 0.0024 ms-1. For a 0.4m circuit, what would the current be if there was only a 4 coulomb charge in 1 second?(B) Plot a current time graph for a circuit where charge was 10C after a second, and doubled every second after that(A) Could a current time graph ever havea negative gradient? Plot one and try todescribe what it would mean

Van der Graaf Negative Electrons

10-4 Coulomb Charge

Electricity Voltage Less

Speed Time 104

On the electric chair..(C) If the chair’s total charge is 1x104C, and a constant current of 1x102A flows, work out how long it takes to work. Assuming there is 50cm between the chair arms, what is the speed of electrons in skin?

(B) Sketch the current time graph like?

(A) Why might the graph look like p90?

Learning Objective: To combine understanding of current and charge

The big question:How can we summarize electricity, current and charge

A – Predict current time graphs using chargeB – Evaluate current time graphsC – Link speed = distance / time and chargeD – Calculate charge, current or time