Exam 18: Magnetism

A straight wire that is 0.60 m and carrying a current of 2.0 A is placed at an angle with respect to the 0.30-T $\vec { B }$ field.If the magnetic force exerted on the wire has a magnitude of 0.18 N,what angle does the wire make with respect to the $\vec { B }$ field?

A charged particle is injected into a uniform magnetic field such that its velocity vector is perpendicular to the $\vec { B }$ field lines.Ignoring the force that Earth exerts on the particle,the particle will

A proton has an initial velocity to the south but is observed to curve upward as the result of a magnetic field.This $\vec { B }$ field must have a component

A wire lying in the plane of this page carries a current directly toward the top of the page.What is the direction of the magnetic force this current-carrying wire exerts on an electron that is moving perpendicular to the page and outward from it on the left side of the wire?

When the switch is closed in the circuit shown in the figure,the wire between the poles of the horseshoe magnet deflects upward.From this you can conclude that the left end of the magnet is

A flat circular coil of wire having 200 turns and diameter 6.0 cm carries a current of 7.0 A.It is placed in a $\vec { B }$ field of $0.60 \mathrm {~T}$ with the plane of the coil making an angle of 30° with the $\vec { B }$ field vector.What is the magnitude of the magnetic torque exerted on the coil?

If a calculated quantity has units of T ∙ m/A,that quantity could be

A wire in the shape of an "M" lies in the plane of the paper.It carries a current of 2.0 A,from A to E,as shown in the figure.It is placed in a uniform 0.65-T $\vec { B }$ field in the same plane,directed as shown on the right side of the figure.The figure indicates the dimensions of the wire.Note that AB is parallel to DE and to the baseline from which the $\vec { B }$ field direction is measured.What are the magnitude and direction of the magnetic force exerted on section BC of this wire?

A positive charge is moving to the right,an upward magnetic force exerted on it,as shown in the figure.In which direction must the $\vec { B }$ field have a component?

A proton,moving east,enters a magnetic field.Because of this magnetic field the proton curves downward.We may conclude that the $\vec { B }$ field must have a component

A charged particle is observed traveling in a circular path of radius R in a uniform magnetic field.If the particle were traveling twice as fast,the radius of the circular path would be

A flat square coil of wire measures 9.5 cm on each side and contains 175 turns of very thin wire.It carries a current of 6.3 A in a uniform 0.84-T $\vec { B }$ field.What angle less than 90° should the plane of this coil make with the $\vec { B }$ field direction so that the magnitude of the magnetic torque exerted on it is 6.5 N ∙ m?

At what distance from a long straight wire carrying a current of 5.0 A is the magnitude of the $\vec { B }$ field due to the wire equal to the Earth's $\vec { B }$ field of about 5.0 × 10^-5 T? (μ₀ = 4π × 10^-7 T ∙ m/A)

In the figure,a small particle of charge -1.9 x $10^{ - 6}$ C and mass $m = 3.1 \times 10 ^{- 12} \mathrm {~kg}$ has speed $v _ { 0 } = 8.1 \times 10 ^ { 3 } \mathrm {~m} / \mathrm { s }$ as it enters a region of uniform magnetic field.The particle is initially traveling perpendicular to the magnetic field and is observed to travel in the semicircular path shown with radius R = 5.0 cm.Find the magnitude and direction of the $\vec { B }$ field in the region.

A long wire carrying a 2.0-A current is placed along the y-axis.What is the magnitude of the $\vec { B }$ field at a point that is 0.60 m from the origin along the x-axis? (μ₀ = 4π × 10^-7 T ∙ m/A)

A proton moving eastward with a velocity of 5.0 km/s enters a magnetic field of 0.20 T pointing northward.What are the magnitude and direction of the force that the magnetic field exerts on the proton? (e = 1.60 × 10^-19C)

An electron,moving west,enters a magnetic field.Because of this field the electron curves upward.We may conclude that the $\vec { B }$ field must have a component

A horizontal wire carries a current straight toward you.From your point of view,the $\vec { B }$ field caused by this current

Two long parallel wires are placed side-by-side on a horizontal table.If the wires carry current in the same direction,

A rectangular coil,with corners labeled ABCD,has length L and width w.It is placed between the poles of a magnet,as shown in the figure.If there is a current I through this coil in the direction shown,what is the direction of the force exerted on section AB of this coil?