MR. SURRETTE VAN NUYS HIGH SCHOOL
CHAPTER 14: MAGNETISM AND E/M INDUCTION MAGNETISM AND E/M INDUCTION WORKSHEET
(Equations: r = (mv)/(qB), = BnIAsin F = BILsin, T = (2m)/(qB), FB = qvBsinFE = Eq,
F / L = oI1I2 / 2r, B = onI, = BAcos, = / t Conversion: T = N.s/C.m)
1. A circular loop carrying a current of 1.42 A is oriented in a magnetic field of 2.74 T. The loop has an area of 0.17 m2 and is mounted on an axis, perpendicular to the magnetic field, which allows the loop to rotate. What is the torque on the loop when its plane is oriented at a 18.0o angle to the field? [ANS: 0.63 N.m]
2. A current-carrying wire of length 0.41 m is positioned perpendicular to a uniform magnetic field. If the current is 12.5 A and it is determined that there is a resultant force of 4.05 N on the wire due to the interaction of the current and field, what is the magnetic field strength? [ANS: 0.79 T]
3. A charged particle, mass 3.51 x 10-25 kg and charge 3.24 x 10-11 C, moves in a circular orbit perpendicular to a uniform magnetic field of 0.75 T. Find the time for the proton to make one complete circular orbit. [ANS: 9.08 x 10-14 s]
4. An electron moves through a region of crossed electric and magnetic fields. The electric field E = 1225 V/m and is directed straight down. The magnetic field B = 1.15 T and is directed to the left. For what velocity v of the electron into the paper (perpendicular to the plane) will the electric force exactly cancel the magnetic force? [ANS: 1065 m/s]
5. A proton is released such that its initial velocity is from left to right across this page. The proton’s path, however, is deflected in a direction toward the bottom edge of the page due to the presence of a uniform magnetic field. What is the direction of this field? (A) out of the page (B) into the page (C) from bottom edge to top edge (D) from right to left across page (E) from left to right across page
6. Two parallel cables of a high voltage transmission line carry equal and opposite currents of 2215 A. The distance between the cables is 1.17 m. What is the magnetic force acting on a 21.0 meter length of each cable? [ANS: 55.3 N]
7. A square loop (L = 0.200 m) consists of 50 closely-wrapped turns which each curry a current of 0.500 A. The loop is oriented as shown in a uniform magnetic field of 0.40 T directed in the positive y direction. What is the magnitude of the torque on the loop? [ANS: 0.35 N.m]
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8. A superconducting solenoid is to be designed to generate a magnetic field of 14.7 T. If the solenoid winding has 1715 turns/meter, what is the required current? [ANS: 6821 A]
9. A positive charge and a negative charge enter a region where the magnetic field is uniform and into the page (between the poles of a magnet with a square cross section). Describe the deflections of each charge:
10. The two charges now travel antiparallel to a uniform magnetic field, as shown below. Describe the deflections of each charge:
11. A long straight wire passes through a region where the magnetic field is uniform and directed out of the page. The current is directed to the top of the page:
11a. What is the direction of the magnetic force on the wire? 11b. Calculate the magnitude of the force. [ANS: 0.80 N]
12. A square loop 1.50 m on a side is placed in a magnetic field of 0.150 T. If the field makes an angle of 12.0o with the normal to the plane of the loop, determine the magnetic flux through the loop. [ANS: 3.30 x 10-1 T.m2]
13. A 125-turn solenoid (r = 0.35 m) is placed in a magnetic field of 0.225 T. The field makes a 75o angle with the normal to the plane of the loop. The magnetic field then decreases to zero in 0.1 s. Determine the average voltage induced during this time interval. [ANS: 28.0 V]
14. A wire loop (r = 0.4 m) is placed in a magnetic field of 1.20 T. The field makes a 45o angle to the plane of the loop. The wire loop is shrunk to a radius of 0.05 m in 0.07 s. Determine the average voltage induced during this time interval. [ANS: 6.00 V]
15. A 0.41 m wire is moved perpendicular to a 0.58 T magnetic field at a speed of 2.50 m/s. What emf is induced across the ends of the wire? [ANS: 0.59 V]
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