UNIT 7 EXERCISES

 

1) A capacitor is connected to a 120V battery as shown in the following diagram. A very high resistance wire is then inserted, connecting point A and B on the plates.

 

The potential difference between the ends of the wire will then be

 

 

2) A pacemaker sends a pulse to a patientís heart every time the capacitor in the pacemaker charges to a voltage of 0.25V. It is desired that the patient receive 75 pulses per minute. Given that the capacitance of the pacemaker is 110mF and that the battery has a voltage of 9.0V, what value should the resistance have? Show your work.

 

3) The current flowing through the 8.45W resistor in the diagram below is 1.22A.

 

(i) What is the voltage of the battery? Explain your reasoning.

 

(ii) if the 17.2W resistor is increased in value, will the current provided by the battery increase, decrease or stay the same? Explain your reasoning.

 

(iii) If the current through the 13.8W resistor is 0.750A, find the current in the other resistors in the circuit. Show your work.