Question 5: A magnet is dropped into a long copper tube with its South pole facing downwards. As the south pole approaches the top end of the tube, deduce the direction of the induced magnetic field around the tube, when viewed from above the top of the tube. When the magnet has just left the bottom of the tube, what will be the direction the induced magnetic field when viewed from above the top of the tube?

Question 5: A magnet is dropped into a long copper tube with its South pole facing downwards. As the south pole approaches the top end of the tube, deduce the direction of the induced magnetic field around the tube, when viewed from above the top of the tube. When the magnet has just left the bottom of the tube, what will be the direction the induced magnetic field when viewed from above the top of the tube?

University Physics Volume 2

18th Edition

ISBN:9781938168161

Author:OpenStax

Publisher:OpenStax

Chapter13: Electromagnetic Induction

Section: Chapter Questions

Problem 66AP: A metal bar of length 25 cm is placed perpendicular to a uniform magnetic field of strength 3 T. (a)...

See similar textbooks

Similar questions

Suppose the parallel-plate capacitor shown below is accumulating charge at a rate of 0.010 C’s. What is the induced magnetic field at a distance of 10 cm from the capacitator?
A time-dependent uniform magnetic field of magnitude B(t) is confined in a cylindrical region of radius R. A conducting rod of length 2D is placed in the region, as shown below. Show that the emf between the ends of the rod is given by dBdtDR2D2 . ( Hint: To find the between the ends, we need to integrate the electric field from one end to the other. To find the electric field, use Faraday’s law as “Ampere’s law for E”.)
Show that the magnetic field at a distance r from the axis of two circular parallel plates, produced by placing charge Q(t) on the plates is Bind=02rdQ(t)dt
A flat loop of wire consisting of a single turn of cross-sectional area 8.00 cm2 is perpendicular to a magnetic field that increases uniformly in magnitude from 0.500 T to 2.50 T in 1.00 s. What is the resulting induced current if the loop has a resistance of 2.00 ?
A thin conducting bar (60.0 cm long) aligned in the positive y direction is moving with velocity v=(1.25m/s)i in a region with a spatially uniform 0.400-T magnetic field directed at an angle of 36.0 above the xy plane. a. What is the magnitude of the emf induced along the length of the moving bar? b. Which end of the bar is positively charged?
A toroid has a major radius R and a minor radius r and is tightly wound with N turns of wire on a hollow cardboard torus. Figure P31.6 shows half of this toroid, allowing us to see its cross section. If R r, the magnetic field in the region enclosed by the wire is essentially the same as the magnetic field of a solenoid that has been bent into a large circle of radius R. Modeling the field as the uniform field of a long solenoid, show that the inductance of such a toroid is approximately L=120N2r2R Figure P31.6
A metal bar of length 25 cm is placed perpendicular to a uniform magnetic field of strength 3 T. (a) Determine the induced emf between the ends of the rod when it is not moving, (b) Determine the emf when the rod is moving perpendicular to its Length and magnetic field with a speed of 50 cm/s.
The magnetic field between the poles of a horseshoe electromagnet is uniform and has a cylindrical symmetry about an axis from the middle of the South Pole to the middle of the North Pole. The magnitude of the magnetic field changes as a rate of dB/dt due to the changing current through the electromagnet, Determine the electric field at a distance r from the center.
Suppose a uniform magnetic field is perpendicular to the 81211-in. page of your homework and a rectangular metal loop lies on the page. The loops sides line up with the edges of the page. The magnetic field is changing with time as described by B = 3.75 103 t, where B is in teslas and t is in seconds. a. Is the magnetic field increasing or decreasing? b. Find the magnitude of the emf induced in the loop.
Is the work required to accelerate a rod from rest to a speed v in a magnetic field greater than the final kinetic energy of the rod? Why?
Is Ampere’s law valid for all closed paths? Why isn’t it normally useful for calculating a magnetic field?
A parallel-plate capacitor with plate separation d is connected to a source of emf that places a time-dependent voltage V(t) across its circular plates of radius r0and area (a) Write an expression for the time rate of change of energy inside the capacitor in terms of V(t) and dV(t)/ dt. (b) Assuming that V(t) is increasing with time, identify the directions of the elecuic field lines inside the capacitor and of the magnetic field lines at the edge of the region between the plates, and then the direction of the Poynting vector S at this location. (c) Obtain expressions for the time dependence of E(t), for B(t) from the displacement current, and for the magnitude of the Poynting vector at the edge of the region between the plates. (d) From S , obtain an expression In terms of ‘(t) and dV(t)/dt for the rate at which electromagnetic field energy the region between the plates. (e) Compare the results of pails (a) and (d) and explain the relationship between them.