A TMS (transcranial magnetic stimulation) device creates very rapidly changing magnetic fields. The field near a typical pulsed-field machine rises from 0 T to 2.5 T in 200 μs. Suppose a technician holds his hand near the device so that the axis of his 1.9-cm-diameter wedding band is parallel to the field. What emf is induced in the ring as the field changes? If the band is made of a gold alloy with resistivity 6.2×10−8Ω⋅m and has a cross-section area 4.5 mm2 , what is the induced current?

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Suppose a magnetic field B(t) oscillates with frequency w. A circular loop of copper lies perpendicular to the magnetic field. The radius of the circular loop is r. a. Write down an expression for the magnetic field as a function of time. Determine the induced emf & in the loop of wire and use this to calculate the current generated in the loop as a function of time. b. What is the power dissipation in the wire as a function to time? Make a sketch of this function. What is the average power Pave dissipation in the wire? Hint: what is the average value of the function you sketched? C. Recall that power is a rate of energy transfer, and that power dissipated by a resistor leads to a change in the thermal energy of the material (in this case the copper wire). We can relate a change in thermal energy to a change in temperature by AT where M is the total mass and c ΔΕth Mc is the specific heat capacity of the material (see page 526 for details). Find an expression for a dT - differential…

A large power plant generates electricity at 12.0 kV. Its old transformer once converted the voltage to 360 kV. The secondary coil of this transformer is being replaced so that its output can be 770 kV for more efficient cross-country transmission on upgraded transmission lines.Randomized Variables V1 = 360 kVV2 = 770 kV a) What is the ratio of turns in the new secondary to the number of turns in the old secondary?  b) What is the ratio of new current output to the old current output for the same power input to the transformer?  c) If the upgraded transmission lines have the same resistance as the original ones, what is the ratio of new line power loss to the old?