Mastering Physics Solutions: Question 20.6

Mastering Physics Solutions: Question 20.6

On May 19, 2012, in Chapter 20: Electromagnetic Induction and Waves, by Mastering Physics Solutions

Part A = south

A bar magnet is thrust toward the center of a circular metallic loop. The magnet approaches perpendicularly with its length perpendicular to the coil’s plane. As the bar recedes from your view and approaches the coil, a clockwise current is induced in the loop. What polarity is that end of the bar magnet nearest the coil?

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Mastering Physics Solutions: Electric and Magnetic Field Vectors Conceptual Question

Mastering Physics Solutions: Electric and Magnetic Field Vectors Conceptual Question

On May 19, 2012, in Chapter 20: Electromagnetic Induction and Waves, by Mastering Physics Solutions

Part A = +z
Part B = -z
Part C = +y
Part D = at a –45° angle in the xz plane

The electric and magnetic field vectors at a specific point in space and time are illustrated. Based on this information, in what direction does the electromagnetic wave propagate?

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Mastering Physics Solutions: Solar Sail

Mastering Physics Solutions: Solar Sail

On May 15, 2012, in Chapter 20: Electromagnetic Induction and Waves, by Mastering Physics Solutions

Part A = Frad = 2IA/c
Part B = mass/area = 0.00160 kg/m2

A solar sail allows a spacecraft to use radiation pressure for propulsion, similar to the way wind propels a sailboat.
Consider a perfectly reflecting mirror oriented so that solar radiation of intensity I is incident upon,
and perpendicular to, the reflective surface of the mirror. If the mirror has surface area A, what is
Frad, the magnitude of the average force due to the radiation pressure of the sunlight on the
mirror?
Suppose that the mirror described in Part A is initially at rest a distance R away from the sun.
What is the critical value of area density for the mirror at which the radiation pressure exactly cancels out the gravitational attraction from the sun?

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Mastering Physics Solutions: Secondary Voltage and Current in a Transformer Ranking Task

Mastering Physics Solutions: Secondary Voltage and Current in a Transformer Ranking Task

On May 15, 2012, in Chapter 20: Electromagnetic Induction and Waves, by Mastering Physics Solutions

Part A = Transformers 1, 2, and 3 have more primary than secondary turns, so they are step down transformers. Transformers 4 and 5 have more secondary turns so are step up transformers.
Part B = From greatest to least: 4 = 5; 2 = 3; 1 Click to use the calculator/solver for this part of the problem
Part C = From greatest to least: 1 = 2 = 3; 4; 5 Click to use the calculator/solver for this part of the problem

Six transformers have the rms primary voltages (Vp), number of primary turns (Np), and number of secondary turns (Ns) listed below.
Which of the transformers are step-up transformers? Which of the transformers are step-down transformers?
Rank the transformers on the basis of their rms secondary voltage.
100 A of rms current is incident on the primary side of each transformer. Rank the transformers on the basis of their rms secondary current.

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Mastering Physics Solutions: The Electromagnetic Spectrum

Mastering Physics Solutions: The Electromagnetic Spectrum

On May 15, 2012, in Chapter 20: Electromagnetic Induction and Waves, by Mastering Physics Solutions

Part A = They have different wavelengths, They have different frequencies, They propagate at different speeds through nonvacuum media depending on both their frequency and the material in which they travel.
Part B = All these technologies use radio waves, including low-frequency microwaves, Microwave ovens emit in the same frequency band as some wireless Internet devices, he radiation emitted by wireless Internet devices has the shortest wavelength of all the technologies listed above, All these technologies emit waves with a wavelength in the range 0.10 to 10.0 m.
Part C = The earth absorbs visible light and emits radiation with a longer wavelength, The earth absorbs visible light and emits radiation with a lower frequency
Part D = 320 nm

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Mastering Physics Solutions: Conceptual Induction

Mastering Physics Solutions: Conceptual Induction

On May 14, 2012, in Chapter 20: Electromagnetic Induction and Waves, by Mastering Physics Solutions

Part A = clockwise
Part B = no current
Part C = counterclockwise

A loop of wire is initially held above a short solenoid. A constant counterclockwise (as viewed from above) current passes through the turns of the solenoid. The loop of wire is steadily lowered, eventually “encircling” the solenoid.
What is the direction of the induced current in the loop when the loop is above the solenoid, moving downward?
What is the direction of the induced current at the instant that the loop is at the midpoint of the solenoid and still moving downward?
What is the direction of the induced current when the loop is below the solenoid and moving downward?

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