A toroid has 250 turns of wire and carries a current of 20 A. Its inner and outer radii are 8.0 and 9.0 cm. What are the values of its magnetic field at r = 8.1, 8.5, and 8.9 cm?

A solenoid 3.0 cm long consists of 9000 loops of wire. If the magnetic field inside the solenoid is measured as 1.0 T, what is the magnitude of the current that flows through it? a 0.037 A b 0.37 A c 2.65 A d 3.05 A e 0.58 A

A cosmic ray proton travels in a circle with a radius of 65 m perpendicular to Earth's magnetic field. If the proton's speed is 2 99 x 10 m/s, then what is the field strength at the proton's location? Assume the proton has a charge of 18 K 10 9C O A 4.3 x 102T O B 21x 10 T C. 72x 1055 T D. 1.4 x 10 50 T

A current of 20.0 mA is maintained in a single circular loop with a circumference of 2.95 m. A magnetic field of 0.735 T is directed parallel to the plane of the loop. What is the magnitude of the torque exerted by the magnetic field on the loop? ? N · m