1. The problem statement, all variables and given/known data i) A particular source of potential difference is capable of providing a maximum potential difference of 2 Volts. Sketch how you would connect two such sources to provide a potential difference of 4 Volts. ii) If each source can provide a current of 20 mA before its potential drops to 1.5 Volts, sketch how you would connect them to provide a curent of 40 mA at 1.5 Volts. iii) A 10 micron length cell in an electric eel produces a potential of around 100 mV for 10 msec. Calculate the average current flowing into the cell during the action potential assuming the charge per unit length flowing into it during the action potential is 100mV (capacitance = 3 × 10−7 F/m) iv) Given the small voltage and current associated with a single cell, explain how an eel produces voltages of the order of 500 V and currents of 80 mA. 2. Relevant equations I = V/R (ohms law) ∆Q = C ∆V 3. The attempt at a solution i) As voltages sum in series circuits I assume this drawing is correct? Any part of the circuit not between the two 2 volt cells will measure 4 volts?. ii) As amperage sums across a parallel circuits and voltages do not I assume that my drawing is correct? I'm going off of the assumption that both cells are now producing 1.5volts due to the electricity having to pass through 2 cells now each lap of the circuit. Would the voltmeter give a reading of 1.5volts (and 40mA even though it shouldn't be able to measure amperage)? iii) 3 × 10−7 F/m x 0.1 V = 3x10^-8C/m. 10um = 1x10^-5m ∆Q= 1x10-5m X 3x10^-8C/m = 3x10^-13C. I also = Coloumbs over seconds so: I = 3x10^-13C over 0.01s = 3x10^-11 Amps = Average cell current? Iv) We want V = 500 and I = 80mA . In order for an eel to produce these numbers I assume that it needs a large mixture of compact series and parallel circuits (cells). First we need 100mV = 500V - Therefore we need 5000 cells in a series (500v/0.1v). In a series each one is still only producing 3x10^-11 Amps while we need 80mA. 8x10^-2A/ 3x10^-11 A = 2666666667 cells in parallel? (Not sure about this calculation). Am I confusing cell number for chain number? I'm having a bit of trouble visualising the actual circuit. Is it 5000 cells one after an other (question i) with 2666666667 parallel circuits coming off of where A is in my drawing of i?