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# Electrodynamics

Question | Answer |
---|---|

Define electrodynamics. | The science of electric charges in motion. |

Under what conditions does an electric current consists of a flow of charged particles? | Gas, Ionic solution, Metallic conductor, Vacuum |

What are the two sources of electric current? | Cells/Batteries and Dynamo/Generator |

Define potential difference. | Difference in electrical potential energy between 2 points in an electric circuit. |

What is the UNIT of potential difference? | Volt |

Define volt. | Potential difference maintaining a current of ampere in a circuit whose resistance is 1 ohm. |

Define electromotive force. | The maximum difference of potential between the terminals of a battery. |

Define current. | Amount of electric charge flowing per second. |

What is the UNIT of current? | Ampere |

What is an ampere? | 1 coulomb quantity of electric charge flowing per second. |

Define resistance. | Property of circuit opposing or hindering flow of electric current. |

What is the UNIT of electrical resistance? | OHM |

Define OHM. | The resistance of a standard volume of mercury under standard conditions. |

On what factors does the resistance of a conductor depend? | Material, Length, Cross-sectional area, and Temperature |

Define dry cell. | Used in flashlights, consists of carbon rod surrounded by manganese dioxide, immersed in ammonium chloride paste, zinc chloride, water. |

Define wet cell. | Consists of hard rubber or plastic case containing sulfuric acid with immersed electrodes. |

How does temperature affect metal conductors? | The resistance becomes greater as the temperature rises. |

Define OHM's law. | The value of the current in a metallic circuit equals the potential difference divided by the resistance. |

Define ammeter. | Meter that measures in amperes. (in series) |

Define voltmeter. | Meter that measures, involts, the potential difference between any two points in a circuit. (in parallel) |

What is the unit of power? | Watt |

What is the equation for power loss? | P = I 2 R watts |

What is the formula that defines power loss in an electrical circuit? | P = I 2 R |

A gasoline engine will convert chemical energy to what type of energy? | Mechanical energy |

What type of charge moves in a conductor? | Negative charges |

What effect does a low temperature have on resistance? | Decreases |

What effect does a high temperature have on resistance? | Increases |

What is measured by a meter wired in series with a resistance? | Current |

Electric insulators inhibit movement of what? | Electric charge |