Download Current is the flow of charge, goes from high Voltage to low Voltage

Day 634
Topic 7: Charges and Circuits
Day Three: Charge and Flow (Voltage, Resistance,
Current)
3rd Quarter

When we return:

1 Day: Q3 Review, discussion (Handed
out today)

I Day: Q3 Exam
Question(s)
Can an object have a charge of .5
coulumbs?
 Yes! A coulumb is a large amount of
fundamental charges.

Can an object have a charge of .5e?
 Nope! That’s half of an electron/proton.

Starting off with a Charge
Remind Me:

What type of Force governs this type of
attraction/repulsion/charge flow?
Lighting up a bulb
The ideas:

The battery: Provided the ‘push’ to make
the charge flow. Has a high point and a
low point.

The electricity: Flowed from high to low,
gave energy to the bulb

The bulb: Restricted the flow, turned
energy into light
The ideas:

The battery: Provided the ‘push’ to make
the charge flow. Has a high point and a
low point.VOLTAGE/POTENTIAL/EMF

The electricity: Flowed from high to low,
gave energy to the bulb CURRENT

The bulb: Restricted the flow, turned
energy into light RESISTANCE
Current
Voltage/ELECTRIC POTENTIAL/EMF
Resistance
Summarize

Remind me… How does
Voltage/Resistance/Current play a role in
electricity powering a bulb?
 Current
is the flow of charge, goes from
high Voltage to low Voltage. Resistance
works against it.
Example Four:

Which of the following changes to a wire will always
bring about an increase in current?
A) Increase voltage and increase resistance
 B) Decrease voltage and decrease resistance
 C) Increase voltage and decrease resistance
 D) Decrease voltage and increase resistance

Example Four:

Which of the following changes to a wire could
bring about an increase in current?
A) Increase voltage and increase resistance
 B) Decrease voltage and decrease resistance
 C) Increase voltage and decrease resistance
 D) Decrease voltage and increase resistance

Example One:
A metal wire is connected between two battery
leads. In an hour, 3 coulumbs flowed. If the wire is
75 ohms,
 A) How much electric potential is there on the
wire?

Example Two:
A metal wire is connected between two battery
leads. In an hour, 3 coulumbs flowed. If the wire is
75 ohms,
 B) If the high lead is 3 volts, what is the low?

Example Five:You Try

An outlet has two prongs, + (120 volts) and – (0
volts).You place a 20Ω wire from the + prong to a
30 volt battery. The battery charges in 20 minutes.
How much charge flowed?