COLLEGE PHYSICS
2nd Edition
ISBN: 9781711470832
Author: OpenStax
Publisher: XANEDU
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Textbook Question
Chapter 21, Problem 29CQ
If a potentiometer is used to measure cell emfs on the order of a few volts, why is it most accurate for the standard emfs to be the same order of magnitude and the resistances to be in the range of a few ohms?
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Chapter 21 Solutions
COLLEGE PHYSICS
Ch. 21 - Prob. 1CQCh. 21 - Prob. 2CQCh. 21 - Prob. 3CQCh. 21 - Prob. 4CQCh. 21 - Prob. 5CQCh. 21 - Knowing that the severity of a shock depends on...Ch. 21 - Would your headlights dim when you start your...Ch. 21 - Some strings of holiday lights are wired in series...Ch. 21 - If two household lightbulbs rated 60 W and 100 W...Ch. 21 - Suppose you are doing a physics lab that asks you...
Ch. 21 - Before World War II, some radios got power through...Ch. 21 - Some light bulbs have three power settings (not...Ch. 21 - Is every emf a potential difference? Is every...Ch. 21 - Prob. 14CQCh. 21 - Given a battery, an assortment of resistors, and a...Ch. 21 - Two different 12-V automobile batteries on a store...Ch. 21 - What are the advantages and disadvantages of...Ch. 21 - Semitractor trucks use four large 12-V batteries....Ch. 21 - Prob. 19CQCh. 21 - Prob. 20CQCh. 21 - Prob. 21CQCh. 21 - Prob. 22CQCh. 21 - Prob. 23CQCh. 21 - Prob. 24CQCh. 21 - Suppose you are using a multimeter (one designed...Ch. 21 - Prob. 26CQCh. 21 - Prob. 27CQCh. 21 - Why can a null measurement be more accurate than...Ch. 21 - If a potentiometer is used to measure cell emfs on...Ch. 21 - Regarding the units involved in the relationship t...Ch. 21 - The RC time constant in heart defibrillation is...Ch. 21 - When making an ECG measurement, it is important to...Ch. 21 - Prob. 33CQCh. 21 - Prob. 34CQCh. 21 - Prob. 35CQCh. 21 - Prob. 36CQCh. 21 - A long, inexpensive extension cord is connected...Ch. 21 - Prob. 38CQCh. 21 - Prob. 39CQCh. 21 - (a) What is the resistance often 275-O resistors...Ch. 21 - (a) What is the resistance of a 1.00 102-O, a...Ch. 21 - What are the largest and smallest resistances you...Ch. 21 - An 1800-W toaster, a 1400-W electric frying pan,...Ch. 21 - Your car’s 30.0-W headlight and 2.40-kW starter...Ch. 21 - (a) Given a48.0-V battery and 24.0-O and 96.0-O...Ch. 21 - Referring to the example combining series and...Ch. 21 - Referring to Figure 21.6: (a) Calculate P3 and...Ch. 21 - Refer to Figure 21.7 and the discussion of lights...Ch. 21 - Prob. 10PECh. 21 - Show that if two resistors R1and R2are combined...Ch. 21 - Unreasonable Results Two resistors, one having a...Ch. 21 - Unreasonable Results Two resistors, one having a...Ch. 21 - Standard automobile batteries have six lead-acid...Ch. 21 - Car bon-zinc dry cells (sometimes referred to as...Ch. 21 - What is the output voltage of a 3.0000-V lithium...Ch. 21 - (a) What is the terminal voltage of a large 1.54-V...Ch. 21 - What is the internal resistance of an automobile...Ch. 21 - (a) Find the terminal voltage of a 12.0-V...Ch. 21 - A car battery with a 12-V emf and an internal...Ch. 21 - The hot resistance of a flashlight bulb is 2.30 ,...Ch. 21 - The label or a portable radio recommends the use...Ch. 21 - An automobile starter motor has an equivalent...Ch. 21 - A child’s electronic toy is supplied by three...Ch. 21 - (a) What is the internal resistance of a voltage...Ch. 21 - A person with body resistance between his hands of...Ch. 21 - Electric fish generate current with biological...Ch. 21 - Integrated Concepts A 12.0-V emf automobile...Ch. 21 - Unreasonable Results A 1.58-V alkaline cell with a...Ch. 21 - Unreasonable Results (a) What is the internal...Ch. 21 - Prob. 31PECh. 21 - Prob. 32PECh. 21 - Verify the second equation in Example 21.5 by...Ch. 21 - Verify the third equation in Example 21.5 by...Ch. 21 - Prob. 35PECh. 21 - Prob. 36PECh. 21 - Prob. 37PECh. 21 - Prob. 38PECh. 21 - Solve Example 21.5, but use loop abcdefgha instead...Ch. 21 - Prob. 40PECh. 21 - Prob. 41PECh. 21 - What is the sensitivity of the galvanometer (that...Ch. 21 - What is the sensitivity of the galvanometer (that...Ch. 21 - Find the resistance that must be placed in series...Ch. 21 - Find the resistance that must be placed in series...Ch. 21 - Find the resistance that must be placed in series...Ch. 21 - Find the resistance that must be placed in...Ch. 21 - Find the resistance that must be placed in series...Ch. 21 - Find the resistance that must be placed in...Ch. 21 - Prob. 50PECh. 21 - Suppose you measure the terminal voltage of a...Ch. 21 - A certain ammeter has a resistance of 5.00X10-5 ...Ch. 21 - A 1,00-?O voltmeter is placed in parallel with a...Ch. 21 - A 0.0200- ammeter is placed in series with a...Ch. 21 - Unreasonable Results Suppose you have a 40.0-...Ch. 21 - Unreasonable Results (a) What resistance would you...Ch. 21 - What is the emf x of a cell being measured in a...Ch. 21 - Calculate the emfx of a dry cell for which a...Ch. 21 - When an unknown resistance Rxis placed in a...Ch. 21 - To what value must you adjust R3to balance a...Ch. 21 - (a) What is the unknown emfx in a potentiometer...Ch. 21 - Suppose you want to measure resistances in the...Ch. 21 - The timing device in an automobile’s intermittent...Ch. 21 - A heart pacemaker fires 72 times a minute, each...Ch. 21 - The duration of a photographic flash is related to...Ch. 21 - A 2.00- and a 7.50-F capacitor can be connected in...Ch. 21 - After two time constants, what percentage of the...Ch. 21 - A 500- resistor, an uncharged 1.50-F capacitor and...Ch. 21 - A heart defibrillator being used on a patient has...Ch. 21 - An ECG monitor must have an RC time constant less...Ch. 21 - Prob. 71PECh. 21 - Using the exact exponential treatment, find how...Ch. 21 - Using the exact exponential treatment, find how...Ch. 21 - Integrated Concepts If you wish to take a picture...Ch. 21 - Integrated Concepts A flashing lamp in a Christmas...Ch. 21 - Integrated Concepts A 160F capacitor charged to...Ch. 21 - Unreasonable Results (a) Calculate the capacitance...Ch. 21 - Construct Your Own Problem Consider a camera's...Ch. 21 - Construe! Your Own Problem Consider a rechargeable...Ch. 21 - Prob. 1TPCh. 21 - Prob. 2TPCh. 21 - Prob. 3TPCh. 21 - Prob. 4TPCh. 21 - Prob. 5TPCh. 21 - Prob. 6TPCh. 21 - Prob. 7TPCh. 21 - Prob. 8TP
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