Principles of Physics: A Calculus-Based Text
5th Edition
ISBN: 9781133104261
Author: Raymond A. Serway, John W. Jewett
Publisher: Cengage Learning
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Chapter 21, Problem 6P
Figure P21.6 represents a section of a conductor of nonuniform diameter carrying a current of I = 5.00 A. The radius of cross-section A1 is r1 = 0.400 cm. (a) What is the magnitude of the current density across A1? The radius r2 at A2 is larger than the radius r1 at A1. (b) Is the current at A2 larger, smaller, or the same? (c) Is the current density at A2 larger, smaller, or the same? Assume A2 = 4A1. Specify the (d) radius, (e) current, and (f) current density at A2.
Figure P21.6
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A beam contains 5.1 × 10⁹ doubly charged positive ions per cubic centimeter, all of which are moving north with a speed of 3.0 × 105 m/s. What is (a) the magnitude of the current density and (b) direction of
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The figure below represents a section of a circular conductor of nonuniform diameter carrying a current of I = 4.70 A. The radius of cross-section A₁ is r₁
= 0.420
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TI
A₁
(a) What is the magnitude of the current density across A₁?
A/m²
Assume A₂
The radius ₂ at A₂ is larger than the radius ₁ at A₁.
(b) Is the current at A₂ larger, smaller, or the same?
The current is larger.
The current is smaller.
The current is the same.
=
I
(c) Is the current density at A₂ larger, smaller, or the same?
The current density is larger.
The current density is smaller.
The current density is the same.
2A₁.
(d) Specify the radius at A2.
mm
(e) Specify the current at A₂.
A
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A2
(f) Specify the current density at A₂.
A/m²
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The figure below represents a section of a circular conductor of nonuniform diameter carrying a current of I = 5.30 A. The radius of cross-section A1 is r1 = 0.510 cm.
What is the magnitude (A/m2) of the current density across A1?
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Chapter 21 Solutions
Principles of Physics: A Calculus-Based Text
Ch. 21.1 - Consider positive and negative charges moving...Ch. 21.2 - Prob. 21.2QQCh. 21.2 - When does an incandescent lightbulb carry more...Ch. 21.5 - For the two incandescent lightbulbs shown in...Ch. 21.7 - Prob. 21.5QQCh. 21.7 - With the switch in the circuit of Figure 21.18a...Ch. 21.7 - Prob. 21.7QQCh. 21.9 - Consider the circuit in Figure 21.29 and assume...Ch. 21 - If the terminals of a battery with zero internal...Ch. 21 - Wire B has twice the length and twice the radius...
Ch. 21 - The current-versus-voltage behavior of a certain...Ch. 21 - Prob. 4OQCh. 21 - A potential difference of 1.00 V is maintained...Ch. 21 - Prob. 6OQCh. 21 - A metal wire of resistance R is cut into three...Ch. 21 - The terminals of a battery are connected across...Ch. 21 - Prob. 9OQCh. 21 - Two conducting wires A and B of the same length...Ch. 21 - When resistors with different resistances are...Ch. 21 - When operating on a 120-V circuit, an electric...Ch. 21 - Prob. 13OQCh. 21 - Prob. 14OQCh. 21 - In the circuit shown in Figure OQ21.15, each...Ch. 21 - Prob. 1CQCh. 21 - Prob. 2CQCh. 21 - Prob. 3CQCh. 21 - Referring to Figure CQ21.4, describe what happens...Ch. 21 - When the potential difference across a certain...Ch. 21 - Use the atomic theory of matter to explain why the...Ch. 21 - Prob. 7CQCh. 21 - (a) What advantage does 120-V operation offer over...Ch. 21 - Prob. 9CQCh. 21 - Prob. 10CQCh. 21 - If you were to design an electric heater using...Ch. 21 - Prob. 12CQCh. 21 - Prob. 13CQCh. 21 - Prob. 14CQCh. 21 - Why is it possible for a bird to sit on a...Ch. 21 - Prob. 1PCh. 21 - Prob. 2PCh. 21 - The quantity of charge q (in coulombs) that has...Ch. 21 - Prob. 4PCh. 21 - Prob. 5PCh. 21 - Figure P21.6 represents a section of a conductor...Ch. 21 - Prob. 7PCh. 21 - A 0.900-V potential difference is maintained...Ch. 21 - Prob. 9PCh. 21 - A lightbulb has a resistance of 240 when...Ch. 21 - Prob. 11PCh. 21 - Prob. 12PCh. 21 - While taking photographs in Death Valley on a day...Ch. 21 - Prob. 14PCh. 21 - If the current carried by a conductor is doubled,...Ch. 21 - Prob. 16PCh. 21 - Prob. 17PCh. 21 - Prob. 18PCh. 21 - Prob. 19PCh. 21 - Prob. 20PCh. 21 - Prob. 21PCh. 21 - Prob. 22PCh. 21 - Prob. 23PCh. 21 - Prob. 24PCh. 21 - A 100-W lightbulb connected to a 120-V source...Ch. 21 - Prob. 26PCh. 21 - Prob. 27PCh. 21 - Prob. 28PCh. 21 - A toaster is rated at 600 W when connected to a...Ch. 21 - Prob. 30PCh. 21 - Prob. 31PCh. 21 - Review. A well-insulated electric water heater...Ch. 21 - A battery has an emf of 15.0 V. The terminal...Ch. 21 - Two 1.50-V batterieswith their positive terminals...Ch. 21 - An automobile battery has an emf of 12.6 V and an...Ch. 21 - Prob. 36PCh. 21 - Prob. 37PCh. 21 - Prob. 38PCh. 21 - Consider the circuit shown in Figure P21.39. Find...Ch. 21 - Four resistors are connected to a battery as shown...Ch. 21 - Three 100- resistors are connected as shown in...Ch. 21 - Prob. 42PCh. 21 - Calculate the power delivered to each resistor in...Ch. 21 - Prob. 44PCh. 21 - The ammeter shown in Figure P21.45 reads 2.00 A....Ch. 21 - Prob. 46PCh. 21 - The circuit shown in Figure P21.47 is connected...Ch. 21 - In Figure P21.47, show how to add just enough...Ch. 21 - Taking R = 1.00 k and = 250 V in Figure P21.49,...Ch. 21 - For the circuit shown in Figure P21.50, we wish to...Ch. 21 - In the circuit of Figure P21.51, determine (a) the...Ch. 21 - Jumper cables are connected from a fresh battery...Ch. 21 - Prob. 53PCh. 21 - Prob. 54PCh. 21 - Prob. 55PCh. 21 - Prob. 56PCh. 21 - In the circuit of Figure P21.57, the switch S has...Ch. 21 - Prob. 58PCh. 21 - The circuit in Figure P21.59 has been connected...Ch. 21 - Assume that global lightning on the Earth...Ch. 21 - Prob. 61PCh. 21 - Prob. 62PCh. 21 - Prob. 63PCh. 21 - Prob. 64PCh. 21 - Prob. 65PCh. 21 - An oceanographer is studying how the ion...Ch. 21 - The values of the components in a simple series RC...Ch. 21 - Prob. 68PCh. 21 - Prob. 69PCh. 21 - Prob. 70PCh. 21 - The student engineer of a campus radio station...Ch. 21 - Prob. 72PCh. 21 - A battery has an emf and internal resistance r. A...Ch. 21 - Prob. 74PCh. 21 - Prob. 75PCh. 21 - Prob. 76PCh. 21 - Prob. 77P
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