29. Sources of Magnetic Field

As a proton passes the origin, its velocity is $3.0\times {10}^5\mathrm{m}/\mathrm{s}$in the positive x direction. What is the magnitude of the magnetic field at the point ($12.0\mathrm{cm}$, $5.0\mathrm{cm}$, $0.0\mathrm{cm}$)?

As a proton passes the origin, its velocity is $3.0\times {10}^5\mathrm{m}/\mathrm{s}$ in the positive x direction. What is the direction of the magnetic field at the point ($12.0\mathrm{cm}$, $5.0\mathrm{cm}$, $0.0\mathrm{cm}$)?

A charged particle moving in a magnetic field has a force to the top of the page when it is moving toward the right and the field is into the page. Is this particle positive, negative or neutral?

What is the force on an electron with velocity $\stackrel{\rightharpoonup }{v}=(3.0\times {10}^5\frac{\mathit{m}}{\mathit{s}})\widehat{i}+(4.0\times {10}^5\frac{\mathit{m}}{\mathit{s}})\widehat{k}$ in a region of space with magnetic field $\stackrel{\rightharpoonup }{B}=(2.4\times {10}^{-4}\mathit{T})\widehat{i}$?

The current in a wire varies with time according to the relationship I = 55 A - (0.65 A/s^2)t^2. (b) What constant current would transport the same charge in the same time interval?

The current in a wire varies with time according to the relationship I = 55 A - (0.65 A/s^2)t^2 . (a) How many coulombs of charge pass a cross section of the wire in the time interval between t = 0 and t = 8.0 s? (b) What constant current would transport the same charge in the same time interval?

Compared to an ideal battery, by what percentage does the battery's internal resistance reduce the potential difference across the 20 Ω resistor in FIGURE EX28.24?

a. Load resistor R is attached to a battery of emf and internal resistance r. For what value of the resistance R, in terms of ∈ and r, will the power dissipated by the load resistor be a maximum?