Problem 1CQ: A switch has a variable resistance that is nearly zero when closed and extremely large when open,... Problem 2CQ: What is the voltage across the open switch in Figure 21.43? Problem 3CQ: There is a voltage across an open switch, such as in Figure 21.43. Why, then, is the power... Problem 4CQ: Why is the power dissipated by a closed switch, such as in Figure 21.43, small? Problem 5CQ: A student in a physics lab mistakenly wired a light bulb, battery, and switch as shown in Figure... Problem 6CQ: Knowing that the severity of a shock depends on the magnitude of the current through your body,... Problem 7CQ: Would your headlights dim when you start your car's engine if the wires in your automobile were... Problem 8CQ: Some strings of holiday lights are wired in series to save wiring costs. An old version utilized... Problem 9CQ: If two household lightbulbs rated 60 W and 100 W are connected in series to household power, which... Problem 10CQ: Suppose you are doing a physics lab that asks you to put a resistor into a circuit, but all the... Problem 11CQ: Before World War II, some radios got power through a “resistance cord" that had a significant... Problem 12CQ: Some light bulbs have three power settings (not including zero), obtained from multiple filaments... Problem 13CQ: Is every emf a potential difference? Is every potential difference an emf? Explain. Problem 14CQ: Explain which battery is doing the charging and which is being charged in Figure 21.45. Problem 15CQ: Given a battery, an assortment of resistors, and a variety of voltage and current measuring devices,... Problem 16CQ: Two different 12-V automobile batteries on a store shelf are rated at 600 and 850 “cold cranking... Problem 17CQ: What are the advantages and disadvantages of connecting batteries in series? In parallel? Problem 18CQ: Semitractor trucks use four large 12-V batteries. The starter system requires 24 V, while normal... Problem 19CQ: Call all of the currents going into the junction in Figure 21.46 be positive? Explain. Problem 20CQ: Apply the junction rule to junction b in Figure 21.47. Is any new information gained by applying the... Problem 21CQ: (a) What is the potential difference going from point a to point b in Figure 21.47? (b) What is the... Problem 22CQ: Apply the loop rule to loop afedcba in Figure 21.47. Problem 23CQ: Apply the loop rule to loops abgefa and cbgedc in Figure 21.47. Problem 24CQ: Why should you not connect an ammeter directly across a voltage source as shown in Figure 21.48?... Problem 25CQ: Suppose you are using a multimeter (one designed to measure a range of voltages, currents, and... Problem 26CQ: Specify the points to which you could connect a voltmeter to measure the following potential... Problem 27CQ: To measure currents in Figure 21.49, you would replace a wire between two points with an ammeter.... Problem 28CQ: Why can a null measurement be more accurate than one using standard voltmeters and ammeters? What... Problem 29CQ: If a potentiometer is used to measure cell emfs on the order of a few volts, why is it most accurate... Problem 30CQ: Regarding the units involved in the relationship t = RC, verify that the units of resistance times... Problem 31CQ: The RC time constant in heart defibrillation is crucial to limiting the time the current flows. If... Problem 32CQ: When making an ECG measurement, it is important to measure voltage variations over small time... Problem 33CQ: Draw two graphs of charge versus time on a capacitor. Draw one for charging an initially uncharged... Problem 34CQ: When charging a capacitor, as discussed in conjunction with Figure 21.38, how long does it take for... Problem 35CQ: When discharging a capacitor, as discussed in conjunction with Figure 21.39, how long does it take... Problem 36CQ: Referring to Figure 21.38, draw a graph of potential difference across the resistor versus time,... Problem 37CQ: A long, inexpensive extension cord is connected from inside the house to a refrigerator outside. The... Problem 38CQ: In Figure 21.41. does the graph indicate the time constant is shorter for discharging than for... Problem 39CQ: An electronic apparatus may have large capacitors at high voltage in the power supply section,... Problem 1PE: (a) What is the resistance often 275-O resistors connected in series? (b) In parallel? Problem 2PE: (a) What is the resistance of a 1.00 102-O, a 2.50-k O, and a 4.00-kresistor connected in series?... Problem 3PE: What are the largest and smallest resistances you can obtain by connecting a 36.0-O, a 50.0-O, and a... Problem 4PE: An 1800-W toaster, a 1400-W electric frying pan, and a 75-W lamp are plugged into the same outlet in... Problem 5PE: Your car’s 30.0-W headlight and 2.40-kW starter are ordinarily connected in parallel in a 12.0-V... Problem 6PE: (a) Given a48.0-V battery and 24.0-O and 96.0-O resistors, find the current and power for each when... Problem 7PE: Referring to the example combining series and parallel circuits and Figure 21.6, calculate I3in the... Problem 8PE: Referring to Figure 21.6: (a) Calculate P3 and note how it this module. (b) Find the total power... Problem 9PE: Refer to Figure 21.7 and the discussion of lights dimming when a heavy appliance comes on. (a) Given... Problem 10PE: A 240-kV power transmission line carrying 5.00x102. A is hung from grounded metal towers by ceramic... Problem 11PE: Show that if two resistors R1and R2are combined and one is much greater than the other (R 1 >>R 2 ):... Problem 12PE: Unreasonable Results Two resistors, one having a resistance of 145 , are connected in parallel to... Problem 13PE: Unreasonable Results Two resistors, one having a resistance of 900 k, are connected in series to... Problem 14PE: Standard automobile batteries have six lead-acid cells in series, creating a total emf of 12.0 V.... Problem 15PE: Car bon-zinc dry cells (sometimes referred to as non- alkaline cells) have an emf of 1.54 V, and... Problem 16PE: What is the output voltage of a 3.0000-V lithium cell in a digital wristwatch that draws 0.300 mA,... Problem 17PE: (a) What is the terminal voltage of a large 1.54-V carbon-zinc dry cell used in a physics lab to... Problem 18PE: What is the internal resistance of an automobile battery that has an emf of 12.0 V and a terminal... Problem 19PE: (a) Find the terminal voltage of a 12.0-V motorcycle battery having a 0.600- internal resistance,... Problem 20PE: A car battery with a 12-V emf and an internal resistance of 0.050 is being charged with a current... Problem 21PE: The hot resistance of a flashlight bulb is 2.30 , and it is run by a 1.58-V alkaline cell having a... Problem 22PE: The label or a portable radio recommends the use of rechargeable nickel-cadmium cells (nicads),... Problem 23PE: An automobile starter motor has an equivalent resistance of 0.0500 and is supplied by a 12.0-V... Problem 24PE: A child’s electronic toy is supplied by three 1.58-V alkaline cells having internal resistances of... Problem 25PE: (a) What is the internal resistance of a voltage source if its terminal voltage drops by 2.00 V when... Problem 26PE: A person with body resistance between his hands of 1.00 k accidentally grasps the terminals of a... Problem 27PE: Electric fish generate current with biological cells called electroplaques, which are physiological... Problem 28PE: Integrated Concepts A 12.0-V emf automobile battery has a terminal voltage of 16.0 V when being... Problem 29PE: Unreasonable Results A 1.58-V alkaline cell with a 0.200- internal resistance is supplying 8.50 A... Problem 30PE: Unreasonable Results (a) What is the internal resistance of a 1.54-V dry cell that supplies 1.00 W... Problem 31PE: Apply the loop rule to loop abcdefgha in Figure 21.25 Problem 32PE: Apply the loop rule to loop aedcba in Figure 21.25. Problem 33PE: Verify the second equation in Example 21.5 by substituting the values found for the currents I1 and... Problem 34PE: Verify the third equation in Example 21.5 by substituting the values found for the currents I1 and... Problem 35PE: Apply the junction rule at point a in Figure 21.52. Problem 36PE: Apply the loop rule to loop abcdefghija in Figure 21.52. Problem 37PE: Apply the loop rule to loop akledcba in Figure 21.52. Problem 38PE: Find the currents flowing in the circuit in Figure 21.52. Explicitly show how you follow the steps... Problem 39PE: Solve Example 21.5, but use loop abcdefgha instead of loop akledcba. Explicitly show how you follow... Problem 40PE: Find the currents flowing in the circuit in Figure 21.47. Problem 41PE: Unreasonable Results Consider the circuit in Figure 21.53, and suppose that the emfs are unknown and... Problem 42PE: What is the sensitivity of the galvanometer (that is, what current gives a full-scale deflection)... Problem 43PE: What is the sensitivity of the galvanometer (that is, what current gives a full-scale deflection)... Problem 44PE: Find the resistance that must be placed in series with a 25.0-galvanometer having a 50.0-A... Problem 45PE: Find the resistance that must be placed in series with a 25.0- galvanometer having a 50.0-A... Problem 46PE: Find the resistance that must be placed in series with a 25.0- galvanometer having a 50.0-A... Problem 47PE: Find the resistance that must be placed in paralled with a 25.0- galvanometer having a 50.0A... Problem 48PE: Find the resistance that must be placed in series with a 10.0- galvanometer having a 100A... Problem 49PE: Find the resistance that must be placed in parallel with a 10.0 galvanometer having a 100A... Problem 50PE: Suppose you measure the terminal voltage of a 1.585-V alkaline cell having an internal resistance of... Problem 51PE: Suppose you measure the terminal voltage of a 3.2G0-V lithium cell having an internal resistance of... Problem 52PE: A certain ammeter has a resistance of 5.00X10-5 an its 3.00-A scale and contains a 10.0- ... Problem 53PE: A 1,00-?O voltmeter is placed in parallel with a 75.0kresistor in a circuit, (a) Draw a circuit... Problem 54PE: A 0.0200- ammeter is placed in series with a 10.00- resistor in a circuit, (a) Draw a circuit... Problem 55PE: Unreasonable Results Suppose you have a 40.0- galvanometer with a 25.0-A sensitivity, (a) What... Problem 56PE: Unreasonable Results (a) What resistance would you put in parallel with a 40.0- galvanometer having... Problem 57PE: What is the emf x of a cell being measured in a potentiometer if the standard cell’s emf is 12.0 V... Problem 58PE: Calculate the emfx of a dry cell for which a potentiometer is balanced when Rx= 1,200 , while an... Problem 59PE: When an unknown resistance Rxis placed in a Wheatstone bridge, it is possible to balance the bridge... Problem 60PE: To what value must you adjust R3to balance a Wheatstone bridge, if the unknown resistance Rxis 100 ... Problem 61PE: (a) What is the unknown emfx in a potentiometer that balances when Rxis 10.0 O, and balances when... Problem 62PE: Suppose you want to measure resistances in the range from 10,0 to 10.0 k using a Wheatstone bridge... Problem 63PE: The timing device in an automobile’s intermittent wiper system is based on an RC time constant and... Problem 64PE: A heart pacemaker fires 72 times a minute, each time a 25.0 nF capacitor is charged (by a battery in... Problem 65PE: The duration of a photographic flash is related to an RC time constant, which is 0.100 s for a... Problem 66PE: A 2.00- and a 7.50-F capacitor can be connected in series or parallel, as can a 25.0- and a 100k... Problem 67PE: After two time constants, what percentage of the final voltage, emf, is on an initially uncharged... Problem 68PE: A 500- resistor, an uncharged 1.50-F capacitor and a 6.16-V emf are connected in series, (a) What is... Problem 69PE: A heart defibrillator being used on a patient has an RC time constant of 10.0 ms due to the... Problem 70PE: An ECG monitor must have an RC time constant less than 1.00 102 to be able to measure variations in... Problem 71PE: Figure 21.55 shows how a bleeder resistor is used to discharge a capacitor after an electronic... Problem 72PE: Using the exact exponential treatment, find how much time is required to discharge a 250-? capacitor... Problem 73PE: Using the exact exponential treatment, find how much time is required to charge an initially... Problem 74PE: Integrated Concepts If you wish to take a picture of a bullet traveling at 500 m/s, then a very... Problem 75PE: Integrated Concepts A flashing lamp in a Christmas earring is based on an RC discharge of a... Problem 76PE: Integrated Concepts A 160F capacitor charged to 450 V is discharged through a 31.2-k resistor. (a)... Problem 77PE: Unreasonable Results (a) Calculate the capacitance needed to get an RC time constant of 1,00x103 s... Problem 78PE: Construct Your Own Problem Consider a camera's flash unit. Construct a problem in which you... Problem 79PE: Construe! Your Own Problem Consider a rechargeable lithium cell that is to be used to power a... format_list_bulleted