28. Magnetic Fields and Forces

A long straight wire carries a current of $I$. What is the magnetic field strength at point 1, located a distance $r$ from the wire?

Which statement best describes the magnetic field of Jupiter compared to Earth's magnetic field?

Which of the following devices operates using magnetism rather than electromagnetic radiation?

Singly ionized (one electron removed) atoms are accelerated and then passed through a velocity selector consisting of perpendicular electric and magnetic fields. The electric field is 155 V/m and the magnetic field is 0.0315 T. The ions next enter a uniform magnetic field of magnitude 0.0175 T that is oriented perpendicular to their velocity. (a) How fast are the ions moving when they emerge from the velocity selector? (b) If the radius of the path of the ions in the second magnetic field is 17.5 cm, what is their mass?

A 150 g ball containing 4.00 x 10⁸ excess electrons is dropped into a 125 m vertical shaft. At the bottom of the shaft, the ball suddenly enters a uniform horizontal magnetic field that has magnitude 0.250 T and direction from east to west. If air resistance is negligibly small, find the magnitude and direction of the force that this magnetic field exerts on the ball just as it enters the field.

An open plastic soda bottle with an opening diameter of 2.5 cm is placed on a table. A uniform 1.75 T magnetic field directed upward and oriented 25° from vertical encompasses the bottle. What is the total magnetic flux through the plastic of the soda bottle?

A horizontal rectangular surface has dimensions 2.80 cm by 3.20 cm and is in a uniform magnetic field that is directed at an angle of 30.0° above the horizontal. What must the magnitude of the magnetic field be to produce a flux of 3.10 x 10^-4 Wb through the surface?

A circular area with a radius of 6.50 cm lies in the xy-plane. What is the magnitude of the magnetic flux through this circle due to a uniform magnetic field B = 0.230 T at an angle of 53.1° from the +z-direction?

A flat, square surface with side length $3.40\mathrm{cm}$ is in the xy-plane at $z=0$. Calculate the magnitude of the flux through this surface produced by a magnetic field $B=\left(0.200T\right)i+\left(0.300T\right)j-\left(0.500T\right)k$.

An electron experiences a magnetic force of magnitude 4.60 x10^-15 N when moving at an angle of 60.0° with respect to a magnetic field of magnitude 3.50 x 10^-3 T. Find the speed of the electron.

A particle with mass $1.81\times {10}^{-3}$ $\mathrm{kg}$ and a charge of $1.22\times {10}^{-8}\text{ C}$ has, at a given instant, a velocity $v=(3.00\times {10}^4\text{ m/s})j$. What are the magnitude and direction of the particle's acceleration produced by a uniform magnetic field $B=\left(1.63T\right)i+\left(0.980T\right)j$?