Electricity Review

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Electricity Review
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Topics covered

• Characteristics of Dynamic Electricity
• Intensity
• Resistance
• Potential Difference
• Energy
• Electrical Power
• Work
• Circuit designs

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Characteristics

• Intensity
• A. Definition
• The number of charges that flow past a given
  point in 1 second

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Characteristics

• B. Units
• The Current Intensity is measured in Amperes (A)
• C. Formula
• I q/?t
• Where I Intensity (A)
• q Charges (C)
• ?t variation in time (sec)
• D. In a circuit

A
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Characteristics

• 2. Resistance
• A. Definition
• The ability to slow down the electrons. The
  ability of a material to hinder the flow of the
  electric curent.

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Characteristics

• B. Units
• The Resistance is measured in Ohms (O)
• C. Formula
• V R I
• Where V Potential Difference (V)
• R Resistance (O)
• I Intensity (A)
• D. In a circuit

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Characteristics

• E. Factors affecting resistance
• Nature of the substance
• Better Conductor Less resistance
• Length
• The shorter, the less resistance
• Diameter
• The fatter, the less resistance
• Temperature
• The colder, the less resistance

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Characteristics

• 3. Potential Difference
• Definition
• The amount of energy transferred between two
  points in an electrical circuit.

V
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Characteristics

• B. Units
• The Potential Difference is measured in Volts (V)
• C. Formula
• V E/q
• Where V Potential Difference (V)
• E Electric Energy (J)
• q Charge (C)
• D. In a circuit

V
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Characteristics

• 4. Electrical Power
• A. Definition
• The amount of work an electrical device can
  perform per second or how much energy it can
  transform in a period of time.

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Characteristics

• B. Units
• The Electrical Power is measured in Watts (W)
• C. Formula
• Pe W/?t
• Where Pe Electrical Power (W)
• W Work (J)
• ?t Time Interval (sec)
• Pe V I
• Where Pe Electrical Power (W)
• V Potential Difference (V)
• I Intensity (A)

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Characteristics

• C. Formula (Continued)
• E Pe?t
• Where E Electrical Energy (J or kWh)
• Pe Electrical Power (Pe)
• ?t Time Interval (sec or hours)

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Electrical Circuits
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Electrical Circuits

• Types of electrical circuits
• Series circuit
• Definition
• Circuit that contains only one branch or path for
  the electrons to follow.
• Characteristics
• If one element is defective, the electricity does
  not flow
• The intensity is the same all around the circuit
• The resistance adds up

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Electrical Circuits

• B. Parallel circuit
• Definition
• Circuit that contains at least one branch or
  paths for the electrons to follow.
• Characteristics
• If an element is defective, the elements on that
  particular branch will stop working only
• Resistance is shared (so resistance is lower)
• Current intensity adds up

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Electrical oddities

• A switch must be closed in order to allow the
  energy to flow
• A light will only light up when the electrons
  complete a full circuit (one side of the power
  source to another)