Exam 27: Sources of the Magnetic Field

A particle with charge q = 5 $\mu$ C is moving with velocity .At t = 0,it is located at the origin.The magnetic field at at t = 0 is

A long solenoid with 20 turns per centimeter has a core of iron-silicon.When the current is 1.50 A,the magnetic field inside the core is 4.50 T.The magnetization M is approximately

Use the following figure to answer the next problem: -The tightly wound toroid shown consists of 100 turns of wire,each carrying a current I = 3 A.If a = 12 cm and b = 15 cm,the magnetic field at r = 18 cm,due to the current in this toroid,is (µ₀ = 4 $\pi$ $\times$ 10^-7 N/A²)

A circular loop of wire 10 cm in radius carries a current of 20 A.The axial magnetic field 15 cm from the center of the loop is approximately

The magnetic field at a distance of 50 cm from a long,straight wire carrying a current of 5.0 A is approximately

A wire of radius 0.35 cm carries a current of 75 A that is uniformly distributed over its cross-sectional area.The magnetic field 0.20 cm from the center of the wire is approximately

In a circular loop of wire lying on a horizontal floor,the current is constant and,to a person looking downward,has a clockwise direction.The accompanying magnetic field at the center of the circle is directed

If m = m_B (in a paramagnetic material)for an external magnetic field of 6 T,what fraction of the saturation magnetization is M at 300 K?

The orbital magnetic moment of an atomic electron is

Use the following figure to answer the next problem: -The tightly wound toroid shown consists of 100 turns of wire,each carrying a current I = 3 A.If a = 12 cm and b = 15 cm,the magnetic field at r = 13 cm,due to the current in this toroid,is (µ₀ = 4 $\pi$ $\times$ 10^-7 N/A²)

Diamagnetic materials

The Biot-Savart law is similar to Coulomb's law in that both

Two long,parallel wires are spaced 1 m apart in air,and you have established a current of 1 A in each.The force per unit length that each wire exerts on the other is approximately

The top diagram shows the velocity of a positively charged particle.The direction of the magnetic field due to the moving charge at r is best represented by

Cobalt has a density of 8.90 g/cm³ and a molecular mass of 58.9 g/mol.Its magnetic moment is 1.69 Bohr magnetons (1 Bohr magneton = 9.27 $\times$ 10^-24 A · m²).What is its saturation magnetization?

A long solenoid with 20 turns per centimeter has a core of iron-silicon.When the current is 1.50 A,the magnetic field inside the core is 4.50 T.The applied field _app is approximately

When a sample of liquid is inserted into a solenoid carrying a constant current,the magnetic field inside the solenoid decreases by 0.005%.What is the magnetic susceptibility of the liquid?

What is the direction of the magnetic field around a wire carrying a current perpendicularly into this page?

A long straight wire of radius R carries a current density J = kr A/m² where k is a constant.The magnetic field for r > R is (Hint: Current enclosed .)

A tightly wound solenoid is 15 cm long,has 350 turns,carries a current of 3.0 A,and has an aluminum core ( $\chi$ _m = 2.3 $\times$ 10^-5).If you ignore end effects,you will find that the value of at the center is approximately