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19 Cards in this Set
- Front
- Back
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what is a current?
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movement of electrons through a substance
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what is magnatism?
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one current flowing through a conductor can exert a force on another conductor carrying a current
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what is a magnatic field?
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it is the regoin throughout which a current-carrying conductor exerts its magnatic effect
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what is DC?
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direct current: flow of electrons in a conductor in one direction only
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what is AC?
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alernating current
flow of electrons in one direction then in the opposite |
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what is Volt?
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it is the potential difference which
produces a current of one ampere in a substance when the rate of energy dissipation is one watt |
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what is capacitance?
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the ability of an object to hold electric charge, charge being a measure of the amount of electricity
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what is the SI unit of charge?
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coulomb (C)
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what are the conversion factors between different units of Pressure?
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1 bar = 100 kPa
1 kPa = 10.2 cm H2O = 7.5 mmHg thus 1 bar = 250 mmHg |
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Boyle's law
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at a constant T, P and V are inversly related
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Charle's law
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at a constant pressure, V and T are directly proportional
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Gay-Lussac's law
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at constant V, pressure and temperature are directly proportional
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List the SI units.
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S: seconds
M: meter M: mole A: ampere C: candela K: kelvin K: kelogram |
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define a wave.
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it is a disturbance that travels through a medium, transferring energy but not matter
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what is a sine wave?
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an example of a wave.
represents the path of a point travelling round a circle at a constant speed defined by the function y=sin x |
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Define oscillation/
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Oscillation is the repetitive variation, typically in time, of some measure about a central value (often a point of equilibrium)
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what is the Doppler effect equation?
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V= ∆F. c / 2f0 .cos Ѳ
V: velocity of the reflector (e.g. red blood cells) ∆F: frequency shift F0: frequency of incident sound Ѳ: angle of incident sound |
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what is an electrode?
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An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte or a vacuum)
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what is the piezoelectric material used in ultrasound transducers?
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a synthetic ceramic:
--> lead zirconate titanate |
