Download Practice Quiz #5

Physics 21
Practice Quiz#5
Name _____________________
c 1. (2pts)A proton moving at a speed of 3.8  106 m/s cuts across the lines of a magnetic field at an angle of 70. The
strength of the field is 0.25  104 T. What is the magnitude of the force acting on the proton? (qp = 1.6  1019 C)
SHOW WORK
a. 5.1  1018 N
b. 9.0  1018 N
c. 1.4  1017 N
d. 2.3  1017 N
b 2. (2pts)Assume that a uniform magnetic field is directed into this page. If an electron is released with an initial velocity
directed from the bottom edge to the top edge of the page, which of the following describes the direction of the
resultant force acting on the electron?
SHOW WORK
a. out of the page
b. to the right
c. to the left
d. into the page
a 3. (2pts)A current-carrying wire of length 50 cm is positioned perpendicular to a uniform magnetic field. If the current is
10.0 A and it is determined that there is a resultant force of 3.0 N on the wire due to the interaction of the current and
field, what is the magnetic field strength?
SHOW WORK
a. 0.60 T
b. 1.5 T
c. 1.8  10-3 T
d. 6.7  10-3 T
a 4. Two long parallel wires 40 cm apart are carrying currents of 10 A and 20 A in the same direction. What is the
magnitude of the magnetic field halfway between the wires?
SHOW WORK
a. 1.0 × 10-5 T
b. 2.0 × 10-5 T
c. 3.0 × 10-5 T
d. 4.0 × 10-5 T
d 5. Superconductors can carry very large currents with no resistance. If a superconducting wire is formed into a solenoid
of length 50.0 cm with 500 turns, what is the magnetic field inside the solenoid when the current is 104 A? (µ0 = 4 
107 Tm/A)
SHOW WORK
a. 1.25 T
b. 2.50 T
c. 6.28 T
d. 12.6 T