course Phy 202
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09:31:45 Query problem set 3 #'2 1-6. How do we determine the current in the circuit and the voltage across each resistor when we know the voltage across a series combination of two known resistances?
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RESPONSE --> To find current use the formula I=V/R. To find the voltage across use V=I*R.
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09:33:51 ** To get the current calculate I = V / R, where R is the sum of the two resistances. To get the voltage across each resistor calculate V = I * R for each resistor. **
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RESPONSE --> ok i understand
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09:35:26 How do we determine the current and voltage across each resistor when we know the voltage across a parallel combination of two known resistances?
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RESPONSE --> To find current in each resistor use I=V/R. So the total current is found from the sum of the two currents. The voltage across is equal to the voltage across the combination.
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09:38:32 ** The voltage across both resistors is the same and is equal to the voltage across the combination. The current in each resistor is calculated by I = V / R. The total current is the sum of the two currents. **
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RESPONSE --> ok i understand
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09:40:03 A series circuit contains a capacitor of known capacitance and a resistor of known resistance. The capacitor was originally uncharged before the source voltage was applied, and is in the process of being charged by the source. If we know the charge on the capacitor, how do we find the current through circuit?
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RESPONSE --> If we divide the voltage across the resistor by the resistance we find the current thru the circuit.
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09:42:39 The voltage across the capacitor is equal to the charge divided by capacitance. The voltage across the capacitor opposes the voltage of the source. Since the voltage drop around the complete circuit must be zero, the voltage across the resistor is the difference between source voltage and the voltage across the capacitor. Dividing the voltage across the resistor by the resistance we obtain the current thru the circuit.
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RESPONSE --> ok i understand that the voltage across the capacitor is equal to the charge divided by the capacitance and it opposes the voltage of the source.
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09:44:32 If we know the capacitance and initial charge on a capacitor in series with a resistor of known resistance then how to we find the approximate time required for the capacitor to discharge 1% of its charge through the circuit?
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RESPONSE --> We take 1% of the initial charge and divide it by the current to get the time required to discharge 1% of the charge.
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09:46:17 ** From capacitance and initial charge we find the voltage. From the voltage and the resistance we find the current. We take 1% of the initial charge and divide it by the current to get the approximate time required to discharge 1% of the charge. } This result is a slight underestimate of the time required since as the capacitor discharges the current decreases. **
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RESPONSE --> ok i understand how to find voltage from capactiance and inital charge. Also, I know how to find the current from the voltage and resistance."