**12. In 1932, Ernest Lawrence invented the cyclotron, in which a strong vertical magnetic field acted on high-speed protons. As the protons gained energy, they spiraled out into hori- zontal circular paths of greater and greater radii (see the note above). In the original cyclotron the radius of the outer circle was 35 cm. Find the magnetic field strength required to turn the path of a proton moving at 2 x 107 m/s into a circle of radius 35 cm. [Hint: The charge and

**12. In 1932, Ernest Lawrence invented the cyclotron, in which a strong vertical magnetic field acted on high-speed protons. As the protons gained energy, they spiraled out into hori- zontal circular paths of greater and greater radii (see the note above). In the original cyclotron the radius of the outer circle was 35 cm. Find the magnetic field strength required to turn the path of a proton moving at 2 x 107 m/s into a circle of radius 35 cm. [Hint: The charge and

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter22: Magnetic Forces And Magnetic Fields

Section: Chapter Questions

Problem 1OQ

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Similar questions

Why is the following situation impossible? Figure P28.46 shows an experimental technique for altering the direction of travel for a charged particle. A particle of charge q = 1.00 C and mass m = 2.00 1015 kg enters the bottom of the region of uniform magnetic field at speed = 2.00 105 m/s, with a velocity vector perpendicular to the field lines. The magnetic force on the particle causes its direction of travel to change so that it leaves the region of the magnetic field at the top traveling at an angle from its original direction. The magnetic field has magnitude B = 0.400 T and is directed out of the page. The length h of the magnetic field region is 0.110 m. An experimenter performs the technique and measures the angle at which the particles exit the top of the field. She finds that the angles of deviation are exactly as predicted. Figure P28.46
Two long wires, one of which has a semicircular tend of radius R, are positioned as shown in the accompanying figure. If both wires carry a current I, how far apart must then parallel sections be so that the net magnetic field at P is zero? Does the current in the straight wire flow up or down?
The strengths of the fields in the velocity selector of a Bainbridge mass spectrometer are B = 0.500 T and E=1.2105 Van, and tire strength of the magnetic field that separates the ions is Bo=0.750 T. A stream of singly charged Li ions is found to bend in a circular arc of radius 2.32 cm. What is the mass of the Li ions?
Three long, straight, parallel wires, all carrying 20 A, are positioned as shown in the accompanying figure. What is the magnitude of the magnetic field at the point P?
, A proton, deuteron, and an alpha-particle ae all accelerated from rest through the same potential difference. They then enter the same magnetic field, moving perpendicular to it. Compute the ratios of the radii of their circular paths. Assume that md= 2wmp and ma= 4mp.
A proton (charge +e, mass mp), a deuteron (charge +e, mass 2mp), and an alpha particle (charge +2e, mass 4mp) are accelerated from rest through a common potential difference V. Each of the particles enters a uniform magnetic field B, with its velocity in a direction perpendicular to B. The proton moves in a circular path of radius p. In terms of p, determine (a) the radius rd of the circular orbit for the deuteron and (b) the radius r for the alpha particle.
An alpha-particle ( m=6.641027kg , q=3.21019C ) travels in a circular path of radius 25 cm in a uniform magnetic field of magnitude 1.5 T. (a) What is the speed of the particle? (b) What is the kinetic energy in electron-volts? (c) Through what potential difference must the particle be accelerated in order to give it this kinetic energy?
Consider the mass spectrometer shown schematically in Active Figure 22.12. The magnitude of the electric field between the plates of the velocity selector is 2.50 103 V/m, and the magnetic field in both the velocity selector and the deflection chamber has a magnitude of 0.035 0 T. Calculate the radius of the path for a singly charged ion having a mass m = 2.18 1026 kg.
An electron is accelerated through 2.40 103 V from rest and then enters a uniform 1.70-T magnetic field. What are (a) the maximum and (b) the minimum values of the magnetic force this particle experiences?
An electron is projected into a uniform magnetic field (0.5i+0.8k)T with a velocity of (3.0i+4.0j)106 m/s . What is the magnetic force on the electron?