Passage Problem 20.91: Studying magnetic bacteria. Constants Some types of bacte
ID: 1572971 • Letter: P
Question
Passage Problem 20.91: Studying magnetic bacteria. Constants Some types of bacteria contain chains of ferromagnetic particles parallel to their long axis. The chains act like small bar magnets that align these magnetotactic bacteria with the earth's magnetic field. In one experiment to study the response of such bacteria to magnetic fields, a solenoid is constructed with copper wire, 1.0 mm in diameter, evenly wound in a single layer to form a helical coil of length 40 cm and diameter 12 cm. The wire has a very thin layer of insulation, and the coil sample of magnetotactic bacteria is placed inside the solenoid. The torque on an individual bacterium in the solenoid's magnetic field is proportional to the magnitude of the magnetic field and to the sine of the angle between the long axis of the bacterium and the magnetic-field direction. Part A The solenoid is removed rom the enclosure and then used in a location where the earth's magnetic ield is 50 and points honzo tal y A sample of bacteria is placed in the center of the solenoid, and the same current is applied that produced a magnetic field of 650 T in the lab. Describe the field experienced by the bacteria. The field is still 650 T O is between 550 T and 650 T , depending on how the solenoid is oriented. is between 600 T and 700 , depending on how the solenoid is oriented. is now 700 HT Submit Request Answer Provide Feedback Next>Explanation / Answer
is inbetween 600 micro T and 700 micr T, depending on how the solenoid is oriented.
because, when earth magnetic field and magnetic field due to solenoid are in the same direction, Bnet = 700 micro T
when earth magnetic field and magnetic field due to solenoid are in the opposite direction, Bnet = 600 micro T