PHYS 201 F2020
12/10/2020
Test 3
1. An electron enters a region with a uniform electric and magnetic fields. We know the magnetic
field has magnitude B = 2.3 mT and points in the negative x-direction. The velocity of the electron is
2500 m/s in the positive y-direction. What is the magnitude of the net force acting on the electron if
the electric field has magnitude 3.5 V/m along the positive z-direction?
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PHYS 201 F2020
12/10/2020
2. In the setup below we have a wire of length 55.0 cm and mass of 25.0 grams, suspended by a set
of flexible thin wires. The wire is in a region where the magnetic field has magnitude 0.560 T and
direction as shown. What is the current required to have zero tension on the flexible thin wires?
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PHYS 201 F2020
12/10/2020
3. The diagram below shows four parallel copper wires at the corners of a square with sides d = 15
cm. What are the magnitude and direction of the total magnetic field at the center of the square?
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PHYS 201 F2020
12/10/2020
4. In the arrangement below, the long straight vertical wire carries a current of 27 A and the
rectangular loop a current of 22 A. Assuming a = 1.5 cm, b = 7.5 cm and L =28 cm, calculate the net
resultant magnetic force acting on the loop (must show all work/calculations).
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