Two coils have the same number of circular turns and carry the same current. Each rotates in a magnetic field acting perpendicularly to its axis of rotation. Coil 1 has a radius of 4.0 cm and rotates in a 0.21-T field. Coil 2 rotates in a 0.45-T field. Each coil experiences the same maximum torque. What is the radius (in cm) of coil 2

One kind of e-book display consists of millions of very small spheres that float in a thin fluid layer between two conducting transparent plates. each sphere is black on one side and white on the other, and possesses an electric dipole moment directed from the white side to the black. when an electric field is applied between the plates, the spheres rotate so that their dipole moment lines up with the field. depending on the fields direction, either the black or the white sides of th espheres can be made visible.the dipole moment of the spheres can be modeled as two opposite charges of magnitude 3.5 x 10^-15 c, separated by a distancce of 100 micrometers (um). what is the maximum possible torque on a sphere if the electric field between the transparent plates is 4.0 x 10^5 n/c

2.which choice most accurately explains what happens to the bonds between atoms when water changes to steam, and what becomes of the energy added during this phase change? when water changes to steam bonds between molecules are created. after reaching the boiling point, energy is used to change bond strength and change the kinetic energy of the atoms. when water changes to steam bonds between molecules break apart. after reaching the boiling point, energy is used to break bonds, but does not affect the kinetic energy of the atoms. when water changes to steam bonds between molecules are created. after reaching the boiling point, energy is used to break bonds, but does not affect the kinetic energy of the atoms. when water changes to steam bonds between molecules break apart. after reaching the boiling point, energy is used to change bond strength and change the kinetic energy of the atoms.

The earth's magnetic field, with a magnetic dipole moment of 8.0×1022am2, is generated by currents within the molten iron of the earth's outer core. suppose we model the core current as a 3000-km-diameter current loop made from a 1000-km-diameter “wire.” the loop diameter is measured from the centers of this very fat wire.to decide whether this is a large or a small current density, compare it to the current density of a 7.0 a current in a 2.0-mm-diameter wire.