body to form images. a) To see why an MRI utilizes iron to increase the magnetic field created by a coil, calculate the current needed in a 400-loop-per-meter circular coil 0.665 m in radius to create a 1.1 T field (typica an MRI instrument) at its center with no iron present. 1= ✔A Introducing ferromagnetic materials inside coils greatly increases the magntic field inside the coil a small amount of current. Think about the value of the current you got in part (a). Is that a practic value of current to use? (b) MRIs utilize the magnetic fields of protons. The magnetic field of a proton is approximately like that of a circular current loop 6.5-10-16 m in radius carrying 1.05 104 A. What is the field at the center of such a loop? B= T

1. .A straight wire with length L carries a current I which is directed to the right and is perpendicular to an unknown uniform magnetic field B. A magnetic force F acts on a conductor which is directed downwards. A. Determine the magnitude and the direction of the magnetic field in the region through which the current passes. B. If the angle between the current and the magnetic field is e this time, what would be the new value of the magnitude of the new magnetic force? Pointing System for No. 1: • What are the given in the problem? • What are the unknown variables? • What are the equations that you are going to use? • Solution and answer for Part A. Solution and answer for Part B. L (cm) = 2306 | (A) = 13 F (pN) = 24 O = 61

a. The magnitude of the magnetic field at a distance R from a long straight wire is equal to B. At what distance will the magnitude of the magnetic field be equal to 3B? b. Two long parallel wires carry equal but opposite currents. Are there any points in space where the total magnetic field is equal to zero? If so, where? If not, why not? C. A simple loop circuit contains two sources, a resistive wire, and a switch. It is placed next to a long straight wire carrying a steady current. As soon as the switch is closed, the loop is suddenly pulled towards the long wire. Which source has a greater emf? Justify your answer. eHe E2

1) A straight, stiff, horizontal wire of length 48 cm and mass 28 g is connected to a source of emf by light, flexible leads. A magnetic field of 1.33 T is horizontal and perpendicular to the wire. Find the current necessary to float the wire, that is, find the current for which the magnetic force balances the weight of the wire. A Submit You currently have 0 submissions for this question. Only 10 submission are allowed. You can make 10 more submissions for this question.