Concept explainers
The lightweight glass sphere in FIGURE Q29.1 hangs by a thread. The north pole of a bar magnet is brought near the sphere.
a. Suppose the sphere is electrically neutral. Is it attracted to, repelled by, or not affected by the magnet? Explain.
b. Answer the same question if the sphere is positively charged.
(a)
The effect of a bar magnet on a glass sphere placed near it.
Explanation of Solution
Given Info:
A glass sphere is hanging from a thread and North Pole of a magnet bar is brought near it.
Since magnetic materials are generally made up of iron and other metals. Moreover, this arises because of intrinsic magnetic moment present in the electrons called as electron spin; but here the material is glass and it happens to be an insulator. Hence, glass is not a magnetic material. Therefore, there is no effect of bar magnet over the glass sphere.
(b)
The effect of a bar magnet over a positively charged glass sphere placed near it.
Explanation of Solution
Given Info:
A positively charged glass sphere is hanging from a thread and North Pole of a magnet bar is brought near it.
There is no magnetic force between the glass sphere and bar magnet since they act on moving charges and other metals. There is a weak attraction due to polarization of charges present on the surface of glass if a magnetic bar is present.
Conclusion:
a) No, there is no attraction or repulsion between the glass sphere and the bar magnet.
b) Yes, the charges present on the glass surface are somewhat attracted to bar magnet.
Want to see more full solutions like this?
Chapter 29 Solutions
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics, Books a la Carte Edition; Student Workbook for Physics for Scientists ... eText -- ValuePack Access Card (4th Edition)
Additional Science Textbook Solutions
Conceptual Physics (12th Edition)
Applied Physics (11th Edition)
Conceptual Physical Science (6th Edition)
University Physics with Modern Physics (14th Edition)
Essential University Physics: Volume 1 (3rd Edition)
Physics: Principles with Applications
- (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_forwardFigure P30.11 shows three configurations of wires and the resultant magnetic fields due to current in the wires. What is the direction of the current that gives the resultant magnetic field shown in each case?arrow_forwardA 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_forward
- (a) A physicist performing a sensitive measurement wants to limit the magnetic force on a moving charge in her equipment to less than 1.001012N. What is the greatest the charge can be if it moves at a maximum speed of 30.0 m/s in Earth's field? (b) Discuss whether it would be difficult to limit the charge to less than the value found in (a) by comparing it with typical static electricity' and noting that static is often absent,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_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
- Copy Figure P30.6 and sketch the magnetic field lines that result from the bar magnets shown there.arrow_forwardA 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_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) A physicist performing a sensitive measurement wants to limit the magnetic force on a moving charge in her equipment to less than 1.001012N. What is the greatest the charge can be if it moves at a maximum speed of 30.0 m/s in the Earth’s field? (b) Discuss whether it would be difficult to limit the charge to less than the value found in (a) by competing it with typical static electricity and noting that static is often absent.arrow_forwardA Hall-effect probe operates with a 120-mA current. When the probe is placed in a uniform magnetic field of magnitude 0.080 0 T, it produces a Hall voltage of 0.700 V. (a) When it is used to measure an unknown magnetic field, the Hall voltage is 0.330 V. What is the magnitude of the unknown held? (b) The thickness of the probe in the direction of B is 2.00 mm. Find the density of the charge carriers, each of which has charge of magnitude e.arrow_forwardTwo long, straight wires carry the same current as shown in Figure P30.22. One wire is parallel to the z axis and the other wire is parallel to the x axis as shown. Find an expression for the magnetic field at the origin.arrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningGlencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningAn Introduction to Physical SciencePhysicsISBN:9781305079137Author:James Shipman, Jerry D. Wilson, Charles A. Higgins, Omar TorresPublisher:Cengage Learning