COLLEGE PHYSICS
2nd Edition
ISBN: 9781711470832
Author: OpenStax
Publisher: XANEDU
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Textbook Question
Chapter 21, Problem 56PE
Unreasonable Results (a) What resistance would you put in parallel with a 40.0-Ω galvanometer having a 25.0-μA sensitivity to allow it to be used as an ammeter that has a full-scale deflection for 10.0μΑ? (b) What is unreasonable about this result? (c) Which assumptions are responsible?
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1) In the circuit shown in figure below the batteries have negligible internal resistance and the meters are both
idealized. With the switch S open, the voltmeter reads 15.0 V. (a) Find the emf E of the battery. (b) What will
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a) An electrician wishes to cut a tungsten wire (p = 5.6x10- Qm) that has 200 of resistance. The wire has a radius of 0.750mm. Approximately what length of wire
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| C:/Users/tylrg/Downloads/Hw-7-Electric-circuits-II.pdf
The diagram below shows a small water heater that uses electrical energy to heat water. The
heating element is a small resistor labeled R1oad = 5.0 N immersed in the water. A 20 V ideal emf device
supplies current and there is an adjustable resistor Ra in series. The value of the adjustable resistance
can be changed to be anywhere between 1.0 - 3.0 N. The adjustable resistor is initially set to 2.0 Q and
the switch is closed.
(a) What is the voltage drop across the heating element?
(b) How much energy is supplied by the source if the water heater runs for 10 minutes?
(c) What fraction of this energy is actually used to heat the water? Please express your answer as a
percentage, using only two significant figures.
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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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