Amperes, Volts and Ohms

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Amperes, Volts and Ohms
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• We use different units to measure different
  things
• Time minutes
• Weight Kilograms
• Length Meters
• There are special units to measure electricity
  too!!!!
• Three of the most important ones are
• Ampere, volt and ohm

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Ampere

• The size of an electric current depends on how
  many electrons pass a point in a circuit every
  second
• The greater the number of electrons, the larger
  the current
• Fewer electrons mean a smaller current
• The size of an electric current is measured in
  amperes (amps)
• We can say that ampere is another name for
  electric current

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Volt

• Nothing moves by itself
• A force is needed to make something move
• Electricity needs a force to move it
• Electrons move in a circuit because a force
  pushed them
• The name for the force or pressure that pushed
  electrons is electromotive force
• It is often called EMF
• The strength of the EMF is measured in volts

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OHM

• Ohms measure the resistance to the flow of
  electrons. You know that a wire resists the flow
  of electrons
• The amount of resistance is measured in ohms

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• There is a connection between amps, volts and
  ohms.
• When one changes, there must be a change in one
  or both of the others.
• There is a rule for figuring out these changes.
• Its called OHMs LAW

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OHMs Law

• Ohms law defines the relationships between power
  (P), voltage (E), current (I) and resistance (R)
• One ohm is the resistance value through which one
  volt will maintain a current of one ampere