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| what is the meaning of capacitance, and what is its units? |
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Definition
the capacitance of a capacitor is the charge stored per unit of potentional difference across it. C = Q / V the units a re farads, 1F = 1CV-1 |
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Term
| what is the equation to calculate the energy stored on a capacitor? |
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Definition
W = 1/2 C V2 the unit is joules J |
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Term
1. what is the equation for capacitors in parallel? and how whould you calculate the charge? 2. what is the equation for capacitors in series? |
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Definition
1. Ctotal= C1 + C2 Q = Ctotal x V 2. 1 = 1 + 1 Ctotal C1 C2 |
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Term
| what are the three quantities that change as a capacitor discahrges? |
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Definition
1. The chage stored, Q. 2. the current flowing, I. 3. the p.d across the capacitor, V. |
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Term
| what does the gradient and the area under a charge time graph represent? |
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Definition
the gradient- represents the current the area under teh graph- represents the charge that has flowed from the capacitor. |
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Term
| what are the discharge equations? |
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Definition
1. Q=Q0e-t/CR 2. I = I0e-t/CR 3. V = V0e-t/CR |
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Term
| what is the time constant τ? |
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Definition
| the quatity CR is called the time constant and its unit is seconds. for a R-C circuit (one in which a capacitor discharges through a resistor) |
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