A magnetic field passes through a stationary wire loop, and its magnitude change

Question

A magnetic field passes through a stationary wire loop, and its magnitude changes in time according to the graph in the drawing. The direction of the field remains constant., There are three equal time intervals indicated in the graph: 0 4.0 s, 4.0 8.0 s, and 8.0 12.0 s. The loop consists of 52 turns of wire and has an area of 0.11 m^2. The magnetic field is oriented parallel to the normal to the loop. What is the Induced EMF (epsilon) for each (show at least one setup) 0 - 4 sec 4 - 8 sec 8 - 12 sec A Magneto Hydrodynamic generator has a conducting fluid flowing a 200 m/sec through a perpendicular magnetic field of 0.37 T. The tube has a radius of 4 cm, and has contacts connected to either side of the tube. How much EMF (epsilon) would this arrangement produce in Induced Votage? (epsilon) ___ Volts

Explanation / Answer

In our case EMF induced is given by

E = -NAdB/dt

dB = change in magnetic field in time dt

so in interval

0-4 sec

dB = 0.3 -1.2 = -0.9 T

dt = 4- 0 = 4 sec

so E = -52 *0.11 * -0.9/4 = 1.287 V

for 4 - 8 sec

dB = 0.3-0.3 =0

so E = 0 V

in 8- 12 sec

dB = 0.9 - 0.3 = 0.6

dt = 12- 8 = 4 sec

So E = - 52 * 0.11 *0.6/4 = - 0.858 V

b) EMF produced across the ends of a conductor moving perpendicular to magnetic field is given by

BLv (motional EMF)

v = speed of conductor

L = distance between ends of conductor perpendicular to direction of motion of conductor = diameter of tube in our case

B = magnetic field in that region

using above formula we have

EMF induced = E = BLv = 0.37 * 8* 10-2 *200 = 5.92 V

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.