Download 10.Notes-2015-ResistanceOhmsLaw

V = IR Notes
Voltage- ( ) Units: ____
_________________________________________________________________________________
Current – (
) Units: ______
_________________________________________________________________________________
Resistance – (
) Units: ______
_________________________________________________________________________________
_________________________________________________________________________________
• The current that flows in a circuit depends on the ______________ applied across
the circuit.
• How much current flows will also depend on the ______________
________________ of the circuit.
ELECTRICAL RESISTANCE DEPENDS ON:
1. __________________ of the metal the better the conductor, the more freely the
electrons can move
2. _________________ of the wire the thicker the wire, the more electrons that can
pass through a given area in a certain amount of time
3. ________________ of the wire the longer the wire, the farther the “signal” has to
travel
4. _________________ of the metal the quicker the atoms of the metal vibrate, the
harder for the electrons to move around them
Ohm’s Law Notes
 The amount of current in a circuit is _____________________ proportional to the
voltage impressed across the circuit.
 The amount of current in a circuit is _____________________ proportional to the
resistance of the circuit.
 This relationship between voltage, current, and resistance is called
______________ Law.
OHM’S LAW EQUATION:
I = ____________
V = ____________
R = ____________
UNITS:
This means: a potential difference of 1 V
impressed across a circuit of resistance 1 
will produce a current of _____ A.
Common Resistances and Electric Shock:
 Typical lamp cord has a ________ resistance while a light bulb has a ________
resistance.
 The human body has a resistance that can vary from __________ if you are
soaked with salt water to ______________ if your skin is very dry. Therefore,
water __________________ your resistance and when combined with a potential
difference across your body, it can cause a harmful amount of current to flow
through you.
Electric shock in the body is caused by ___________________(not voltage).
Examples:
1. A 30-V battery is connected to a 10  resistor. What is the current in the circuit?
2. A motor with an operating resistance of 32 is connected to a voltage source. The
current in the circuit is 3.8 A. What is the voltage of the source?