The Defibrillator
A defibrillator is designed to pass a large current through a patient’s torso in order to stop dangerous heart rhythms. Its key part is a capacitor that is charged to a high voltage. The patient’s torso plays the role of a resistor in an RC circuit. When a switch is closed, the capacitor discharges through the patient’s torso. A jolt from a defibrillator is intended to be intense and rapid; the maximum current is very large, so the capacitor discharges quickly. This rapid pulse depolarizes the heart, stopping all electrical activity. This allows the heart’s internal nerve circuitry to reestablish a healthy rhythm.
A typical defibrillator has a 32 μF capacitor charged to 5000 V. The electrodes connected to the patient are coated with a
Which pair of graphs in Figure P23.82 best represents the capacitor voltage and the current through the torso as a function of time after the switch is closed?
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