1. Discuss briefly some applications of Lenz's law in magnetic induction. 2. The current through a 3.2-mH inductor varies with time according to the graph shown in the drawing. What is the average induced emf during the time intervals (a) 0-2.0 ms, (b) 2.0-5.0 ms, and (c) 5.0-9.0 ms? 4.0 I(A) 2.0 5.0 +(ms) 9.0

1. Discuss briefly some applications of Lenz's law in magnetic induction. 2. The current through a 3.2-mH inductor varies with time according to the graph shown in the drawing. What is the average induced emf during the time intervals (a) 0-2.0 ms, (b) 2.0-5.0 ms, and (c) 5.0-9.0 ms? 4.0 I(A) 2.0 5.0 +(ms) 9.0

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter23: Electromagnetic Induction, Ac Circuits, And Electrical Technologies

Section: Chapter Questions

Problem 8PE: Suppose a 50-turn coil lies in the plane of the page in a uniform magnetic field that is directed...

See similar textbooks

Similar questions

(a) A car generator turns at 400 rpm when 1he engine is idling. Its 300-turn, 5.00 by 8.00 cm rectangular coil rotates in an adjustable magnetic field 50 that it can produce suf?cient voltage even at low rpms. What is the field strength needed to produce a 24.0 V peak emf? (b) Discuss how this required field strength compares to those available in permanent and electromagnets.
A copper wire of Length I is fashioned into a circular coil with N turns. When the magnetic field through the coil changes with time, for what value of N is the induced emf a maximum?
The 4.00 A current through a 7.50 mH inductor is switched off in 8.33 ms. What is the emf induced opposing this?
When a magnetic field is first turned on, t1 flux through a 20-turn loop varies with time according to m=5.0t22.0t ,where m is in milliwebers, tis in seconds, and the loop is in the plane of the page with the unit normal pointing outward. (a) What is the emf induced in the loop as a function of time? What is the direction of the induced current at (b) t= 0, (c) 0.10, (d) 1.0, and (e) 2.0 s?
(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.
A 120-V, series-wound dc motor draws 0.50 A from its power source when operating at full speed, and it draws 2.0 A when it starts. The resistance of the armature coils is 10 , (a) What is the resistance of the field coils? (b) What is tire back emf of the motor when it is running at full speed? (c) The motor operates at a different speed and draws 1.0 A from the source. What is the back emf in this case?
A person who works with large magnets sometimes places her head inside a strong field. She reports feeling dizzy as she quickly turns her head. How might this be associated with induction?
What is the peak emf generated by a 0.250 m radius, 500turn coil is rotated one-fourth of a revolution in 4.17 ms, originally having its plane perpendicular to a uniform magnetic field. (This is 60 rev/s.)
What happens to the amplitude of the induced emf when the rate of rotation of a generator coil is doubled? (a) It becomes four times larger. (b) It becomes two times larger. (c) It is unchanged. (d) It becomes one-hall as large. (e) It becomes one-fourth as large.
It you want a characteristic RL time constant of 1.00 s, and you have a 500 (resistor, what value of self-inductance is needed?
Medical 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.)
An 820-turn wire coil of resistance 24.0 is placed on lop of a 12 500-turn, 7.00-cm-long solenoid, as in Figure P20.57. Both coil and solenoid have cross-sectional area of 1.00 104 m2. (a) How long does it take the solenoid current to reach 0.632 times its maximum value? (b) Determine the average back emf caused by the self-inductance of the solenoid during this interval. The magnetic field produced by the solenoid at the location of the coil is one-half as strong as the field at the center of the solenoid. (c) Determine the average rate of change in magnetic flux through each turn of the coil during the stated interval. (d) Find the magnitude of the average induced current in the coil. Figure P20.57