EBK PHYSICS FOR SCIENTISTS AND ENGINEER
9th Edition
ISBN: 8220100581557
Author: Jewett
Publisher: Cengage Learning US
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Chapter 31, Problem 31.5QQ
In an equal-arm balance from the early 20th century (Fig. 31.23), an aluminum sheet hangs from one of the arms and passes between the poles of a magnet, causing the oscillations of the balance to decay rapidly. In the absence of such magnetic braking, the oscillation might continue for a long time, and the experimenter would have to wait to take a reading. Why do the oscillations decay? (a) because the aluminum sheet is attracted to the magnet (b) because currents in the aluminum sheet set up a magnetic field that opposes the oscillations (c) because aluminum is paramagnetic
Figure 31.23 (Quick Quiz 31.5) In an old-fashioned equal-arm balance, an aluminum sheet hangs between the poles of a magnet.
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Write down an expression for the net force along the (tangentially to) arc of motion on a simple pendulum made of a metal rod of the length /and the
mass m carrying the current /. The rod is suspended by the middle on a weightless wire of the length L in the magnetic field B and the gravitational
field g perpendicular to the rod (see picture below). Please use "*" (without the quotes) for products (e.g. B*A), "/" for ratios (e.g. B/A) and the usual
"+" and "-" signs as appropriate. For exponents (e.g. A²) use A*A or A^2 notation: thus A3/B should appear as either A*A*A/B or A^3/B. For greek letters
use "theta" (without the quotes) and for trigonometric functions use "cos", "tan", "sin" (without the quotes). Thus for Acose use A*cos theta. Please
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Side view
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Top view
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Chapter 31 Solutions
EBK PHYSICS FOR SCIENTISTS AND ENGINEER
Ch. 31 - A circular loop of wire is held in a uniform...Ch. 31 - In Figure 30.8a, a given applied force of...Ch. 31 - Figure 30.12 Figure 30.12 shows a circular loop of...Ch. 31 - Prob. 31.4QQCh. 31 - In an equal-arm balance from the early 20th...Ch. 31 - Figure OQS1.I is a graph of the magnetic flux...Ch. 31 - Prob. 31.2OQCh. 31 - A rectangular conducting loop is placed near a...Ch. 31 - A circular loop of wire with a radius of 4.0 cm is...Ch. 31 - A square, flat loop of wire is pulled at constant...
Ch. 31 - The bar in Figure OQ31.6 moves on rails to the...Ch. 31 - A bar magnet is held in a vertical orientation...Ch. 31 - What happens to the amplitude of the induced emf...Ch. 31 - Two coils are placed near each other as shown in...Ch. 31 - A circuit consists of a conducting movable bar and...Ch. 31 - Two rectangular loops of wire lie in the same...Ch. 31 - In Section 7.7, we defined conservative and...Ch. 31 - A spacecraft orbiting the Earth has a coil of wire...Ch. 31 - In a hydroelectric dam, how is energy produced...Ch. 31 - A bar magnet is dropped toward a conducting ring...Ch. 31 - A circular loop of wire is located in a uniform...Ch. 31 - A piece of aluminum is dropped vertically downward...Ch. 31 - Prob. 31.7CQCh. 31 - When the switch in Figure CQ31.8a is closed, a...Ch. 31 - Prob. 31.9CQCh. 31 - A loop of wire is moving near a long, straight...Ch. 31 - A flat loop of wire consisting of a single turn of...Ch. 31 - An instrument based on induced emf has been used...Ch. 31 - Transcranial magnetic stimulation (TMS) is a...Ch. 31 - A 25-turn circular coil of wire has diameter 1.00...Ch. 31 - A circular loop of wire of radius 12.0 cm is...Ch. 31 - A circular loop of wire of radius 12.0 cm is...Ch. 31 - Prob. 31.7PCh. 31 - A strong electromagnet produces a uniform magnetic...Ch. 31 - A 30-turn circular coil of radius 4.00 cm and...Ch. 31 - Scientific work is currently under way to...Ch. 31 - An aluminum ring of radius r1 = 5.00 cm and...Ch. 31 - An aluminum ring of radius r1 and resistance R is...Ch. 31 - Prob. 31.13PCh. 31 - A coil of 15 turns and radius 10.0 cm surrounds a...Ch. 31 - A square, single-turn wire loop = 1.00 cm on a...Ch. 31 - A long solenoid has n = 400 turns per meter and...Ch. 31 - A coil formed by wrapping 50 turns of wire in the...Ch. 31 - When a wire carries an AC current with a known...Ch. 31 - A toroid having a rectangular cross section (a =...Ch. 31 - Prob. 31.20PCh. 31 - A helicopter (Fig. P30.11) has blades of length...Ch. 31 - Use Lenzs law 10 answer the following questions...Ch. 31 - A truck is carrying a steel beam of length 15.0 in...Ch. 31 - A small airplane with a wingspan of 14.0 m is...Ch. 31 - A 2.00-m length of wire is held in an eastwest...Ch. 31 - Prob. 31.26PCh. 31 - Figure P31.26 shows a lop view of a bar that can...Ch. 31 - A metal rod of mass m slides without friction...Ch. 31 - A conducting rod of length moves on two...Ch. 31 - Prob. 31.30PCh. 31 - Review. Figure P31.31 shows a bar of mass m =...Ch. 31 - Review. Figure P31.31 shows a bar of mass m that...Ch. 31 - The homopolar generator, also called the Faraday...Ch. 31 - Prob. 31.34PCh. 31 - Review. Alter removing one string while...Ch. 31 - A rectangular coil with resistance R has N turns,...Ch. 31 - Prob. 31.37PCh. 31 - An astronaut is connected to her spacecraft by a...Ch. 31 - Within the green dashed circle show in Figure...Ch. 31 - Prob. 31.40PCh. 31 - Prob. 31.41PCh. 31 - 100-turn square coil of side 20.0 cm rotates about...Ch. 31 - Prob. 31.43PCh. 31 - Figure P30.24 (page 820) is a graph of the induced...Ch. 31 - In a 250-turn automobile alternator, the magnetic...Ch. 31 - In Figure P30.26, a semicircular conductor of...Ch. 31 - A long solenoid, with its axis along the x axis,...Ch. 31 - A motor in normal operation carries a direct...Ch. 31 - The rotating loop in an AC generator is a square...Ch. 31 - Prob. 31.50PCh. 31 - Prob. 31.51APCh. 31 - Suppose you wrap wire onto the core from a roll of...Ch. 31 - A circular coil enclosing an area of 100 cm2 is...Ch. 31 - A circular loop of wire of resistance R = 0.500 ...Ch. 31 - A rectangular loop of area A = 0.160 m2 is placed...Ch. 31 - A rectangular loop of area A is placed in a region...Ch. 31 - Strong magnetic fields are used in such medical...Ch. 31 - Consider the apparatus shown in Figure P30.32: a...Ch. 31 - A guitars steel string vibrates (see Fig. 30.5)....Ch. 31 - Why is the following situation impossible? A...Ch. 31 - The circuit in Figure P3 1.61 is located in a...Ch. 31 - Magnetic field values are often determined by...Ch. 31 - A conducting rod of length = 35.0 cm is free to...Ch. 31 - Review. A particle with a mass of 2.00 1016 kg...Ch. 31 - The plane of a square loop of wire with edge...Ch. 31 - In Figure P30.38, the rolling axle, 1.50 m long,...Ch. 31 - Figure P30.39 shows a stationary conductor whose...Ch. 31 - Prob. 31.68APCh. 31 - A small, circular washer of radius a = 0.500 cm is...Ch. 31 - Figure P30.41 shows a compact, circular coil with...Ch. 31 - Prob. 31.71APCh. 31 - Review. In Figure P30.42, a uniform magnetic field...Ch. 31 - An N-turn square coil with side and resistance R...Ch. 31 - A conducting rod of length moves with velocity v...Ch. 31 - The magnetic flux through a metal ring varies with...Ch. 31 - A rectangular loop of dimensions and w moves with...Ch. 31 - A long, straight wire carries a current given by I...Ch. 31 - A thin wire = 30.0 cm long is held parallel to...Ch. 31 - Prob. 31.79CPCh. 31 - An induction furnace uses electromagnetic...Ch. 31 - Prob. 31.81CPCh. 31 - A betatron is a device that accelerates electrons...Ch. 31 - Review. The bar of mass m in Figure P30.51 is...
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