A Conducting Rod Whose Length Is $\ell = 27.0 \mathrm {~cm}$

question 130

Multiple Choice

A conducting rod whose length is $\ell = 27.0 \mathrm {~cm}$ is placed on frictionless $U$ -shaped metal rails that is connected to a lightbulb having a resistance of $5.00 \Omega$ as shown in the figure. The rails and the rod are in the plane of the page. A constant uniform magnetic field of strength $1.20 \mathrm {~T}$ is applied perpendicular to and out of the paper. An external applied force moves the rod to the right with a constant speed. At what speed should the rod be pulled so that the lightbulb will consume energy at a rate of $1.10 \mathrm {~W}$ ?

• A) \(4.26 \mathrm {~m} / \mathrm { s }\)
• B) \(3.50 \mathrm {~m} / \mathrm { s }\)
• C) \(7.24 \mathrm {~m} / \mathrm { s }\)
• D) \(6.00 \mathrm {~m} / \mathrm { s }\)
• E) \(2.00 \mathrm {~m} / \mathrm { s }\)

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Definitions:

LIFO Reserve

An accounting method that records the difference between the cost of inventory calculated using the Last-In, First-Out (LIFO) method and another inventory valuation method, often FIFO.

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Beginning Inventory

The value of a company's inventory at the start of an accounting period.

Ending Inventory

The overall worth of merchandise up for sale following the conclusion of an accounting cycle.