ELECTRIC MOTORS
A shunt dynamo has an armature resistance of 0.120
A shunt dynamo has an armature resistance of 0.120
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Schaum's Outline of College Physics, Twelfth Edition (Schaum's Outlines)
- An emf is induced by rotating a 1000-turn, 20.0 cm diameter coil in the Earth’s 5.00105T magnetic field. What average emf is induced, given the plane of the coil is originally perpendicular to me Earth’s field and is rotated to be parallel to the field in 10.0 ms?arrow_forwardA coil of 1000 turns encloses an area of 25 cm2. It is rotated in 0.010 s from a position where its plane is perpendicular to Earth’s magnetic field to one where its plane is parallel to the field. If the strength of the field is 6.0 x I0 T. what is the average emf induced in the coil?arrow_forwardA truck is carrying a steel beam of length 15.0 in on a freeway. An accident causes the beam to be dumped off the truck and slide horizontally along the ground at a speed of 25.0 m/s. The velocity of the center of mass of the beam is northward while the length of the beam maintains an east-west orientation. The vertical component of the Earths magnetic field at this location has a magnitude of 35.0 T. What is the magnitude of the induced emf between the ends of the beam?arrow_forward
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- Integrated Concepts This problem refers to the bicycle generator considered in the previous problem. It is driven by a 1.60 cm diameter wheel that rolls on the outside rim of the bicycle tire. (a) What is the velocity 0f the bicycle if the generator’s angular velocity is 1875 rad/s? (b) What is the maximum emf of the generator when the bicycle moves at 10.0 m/s, noting that it was 18.0 V under the original conditions? (c) If the sophisticated generator can vary its own magnetic field, what field strength will it need at 5.00 m/s to produce a 9.00 V maximum emf?arrow_forward(a) An MRI technician moves his hand from a region of very low magnetic field strength into an MRI scanner's 2.00 T field with his fingers pointing in the direction of the field. Find the average emf induced in his wedding ling, given its diameter is 2.20 cm and assuming it takes 0.250 s to move it into the field. (b) Discuss whether this current would significantly change the temperature of the ring.arrow_forwardMedical devices implanted inside the body are often powered using transcutaneous energy transfer (TET), a type of wireless charging using a pair of closely spaced coils. An emf is generated around a coil inside the body by varying the current through a nearby coil outside the body, producing a changing magnetic flux. Calculate the average induced emf if each 10-turn coil has a radius of 1.50 cm and the current in the external coil varies from its maximum value of 10.0 A to zero in 6.25 106 s. (Hint: Recall from Topic 19 that the magnetic field at the center of the current-carrying external coil is B=N0I2R. Assume this magnetic field is constant and oriented perpendicular to the internal coil.)arrow_forward
- A stationary coil is in a magnetic field that is changing with time. Does the emf induced in the coil depend on the actual values of the magnetic field?arrow_forwardIs an emf induced in the coil in Figure 23.54 when it is stretched? If so, state why and give the direction of the induced current. Figure 23.54 A circular coil of wire is snatched in a magnetic field.arrow_forwardIn the August 1992 space shuttle flight, only 250 m of the conducting tether considered in Example 23.2 could be let out. A 40.0 V motional emf was generated in me Earth’s 5.00105T field, while moving at 7.80103m/s. What was the angle between the shuttle’s velocity and the Earth’s field, assuming the conductor was perpendicular to the field?arrow_forward
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