Concept explainers
MRI (magnetic resonance imaging) is a medical technique that produces detailed “pictures” of the interior of the body. The patient is placed into a solenoid that is 40cm in diameter and 1.0 m long. A 100 A current creates a 5.0 T magnetic field inside the solenoid. To carry such a large current, the solenoid wires are cooled with liquid helium until they become superconducting (no electric resistance).
a. How much magnetic energy is stored in the solenoid? Assume that the magnetic field is uniform within the solenoid and quickly drops to zero outside the solenoid.
b. How many turns of wire does the solenoid have?
Want to see the full answer?
Check out a sample textbook solutionChapter 30 Solutions
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (Chs 1-42) Plus Mastering Physics with Pearson eText -- Access Card Package (4th Edition)
- A circular coil with 200 turns Las a radius of 2.0 cm. (a) What current through tire coil results in a magnetic dipole moment of 3.0 Am2? (b) What is the maximum torque that the coil will experience in a uniform field of strength 5.0102 ? (c) If tire angle between and B is 45°, what is the magnitude of tire torque on the coil? (d) What is the magnetic potential energy of coil for this orientation?arrow_forwardA toroid with an inner radius of 20 cm and an outer radius of 22 cm is tightly wound with one layer of wire that has a diameter of 0.25 mm. (a) How many turns are there on the toroid? (b) If the current through the toroid windings is 2.0 A, what is the strength of the magnetic field at the center of the toroid?arrow_forwardA uniform magnetic field of magnitude is directed parallel to the z-axis. A proton enters the field with a velocity v=(4j+3k)106m/s and travels in a helical path with a radius of 5.0 cm. (a) What is the value of B? (b) What is the time required for one trip around the helix? (c) Where is the proton 5.0107s after entering the field?arrow_forward
- A 20-A current flows through a solenoid with 2000 turns per meter. What is the magnetic field inside the solenoid if its core is (a) a vacuum and (b) filled with liquid oxygen at 90 K?arrow_forwardA 0.50-kg copper sheet drops through a uniform horizontal magnetic field of 1.5 T, and it reaches a terminal velocity of 2.0 m's. (a) What is the net map,-, eh: force on the sheet after it reaches terminal velocity? (b) Describe the mechanism responsible for this force, (c) How much power is dissipated as Joule heating while the sheet moves at terminal velocity?arrow_forward(a) An oxygen16 ion with a mass at 2.661026kg travels at 5.00106m/s perpendicular to a 1.20T magnetic field, which makes it move in a circular arc with a 0.231-m radius. What positive charge is on the ion? (b) What is the radio of this charge to the charge of an electron? (c) Discuss why the radio found in (b) should be an integer.arrow_forward
- (a)What is the angle between a wire carrying an 8.00-A current and the 1.20-T field It Is in if 50.0 cm of the wire experiences a magnetic force of 2.40 N? (b) What is the force on the wire If It Is rotated to make an angle of 90° with the field?arrow_forwardThe current density in the long, cylindrical wire shown in the accompanying figure varies with distance r from the center of the wire according to J = cr. where c is a constant (a) What is the current through the wire? (b) What is the magnetic field produced by this current for r < R? For rR ?arrow_forward(a) What is the speed of a supersonic aircraft with a 17.0-m wingspan, if it experiences a 1.60V Hall voltage between its wing lips when in level flight over the north magnetic pole, where the Earth's field strength is 8.00105T ? (b) Explain why very little current flows as a result of this Hall voltage.arrow_forward
- A conductor consists of a circular loop of radius K and two long, straight sections as shown in Figure P50.7. The wire lies in the plane of the paper and carries a current I. (a) What is the direction of the magnetic field at the center of the loop? (b) Find an expression for the magnitude of the magnetic field at the center of the loop.arrow_forwardUnreasonable results A charged particle having mass 6.641027kg (that of a helium atom) moving at 8.70105m/s perpendicular to a 1.50-T magnetic field travels in a circular path of radius 16.0 mm. (a) What is the charge of the particle? (b) What is unreasonable about this result? (c) Which assumptions are responsible?arrow_forward(a) A proton moving with velocity v=ii experiences a magnetic force F=Fij. Explain what you can and cannot infer about B from this information. (b) What If? In terms of Fi, what would be the force on a proton in the same field moving with velocity v=ii? (c) What would be the force on an electron in the same field moving with velocity v=ii?arrow_forward
- Physics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningGlencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill