76. The figure at right shows a portion of a circuit used to model muscle cells and neurons. All the resistors have the same value R = 1.0 M2, and

the emfs are ɛ1 = 75 mV, ɛ2 = 45 mV and ɛ3 = 20 mV. Calculate the current through ɛ3 and its direction. Interpret: (briefly describe the main ideas/concepts relevant to the solution) Develop: (annotate the diagram, indicating the currents; write equations relating the currents) Evaluate: (use the equations from the Develop step to calculate current through ɛ3)