Fall ’12 PHY 122 Homework Solutions #6 HW6: Ch. 26 P 2, 7, 10,15, 19, 27, 33, 44 Chapter 26 Problem 2 Four 1.50-V cells are connected in series to a 12-Ω lightbulb. If the resulting current is 0.45 A, what is the internal resistance of each cell, assuming they are identical and neglecting the resistance of the wires? Chapter 26 Problem 10 Three 1.70kΩ resistors can be connected together in four different ways, making combinations of series and/or parallel circuits. What are these four ways, and what is the net resistance in each case? Chapter 26 Problem 15 A close inspection of an electric circuit reveals that a 480Ω resistor was inadvertently soldered in the place where a 370Ω resistor is needed. How can this be fixed without removing anything from the existing circuit? Chapter 26 Problem 19 What is the net resistance of the circuit connected to the battery in Fig. 26–41? Chapter 26 Problem 27 Calculate the current in the circuit of Fig. 26–45, and show that the sum of all the voltage changes around the circuit is zero. Chapter 26 Problem 33 Determine the magnitudes and directions of the currents through R1 and R2 in Fig. 26–51. Chapter 26 Problem 44 In Fig. 26–58 (same as Fig. 26–17a), the total resistance is 15.0kΩ and the battery’s emf is 24.0 V. If the time constant is measured to be 24.0μs calculate (a) the total capacitance of the circuit and (b) the time it takes for the voltage across the resistor to reach 16.0 V after the switch is closed.