Shrinking Loop. A circular loop of flexible iron wire has an initial circumference of 160cm , but its circumference is decreasing at a constant rate of 15.0cm/s due to a tangential pull on the wire. The loop is in a constant uniform magnetic field of magnitude 0.800T , which is oriented perpendicular to the plane of the loop. Assume that you are facing the loop and that the magnetic field points into the loop.Part AFind the magnitude of the emf E induced in the loop after exactly time 9.00s has passed since the circumference of the loop started to decrease.Express your answer numerically in volts to three significant figures.Part BFind the direction of the induced current in the loop as viewed looking along the direction of the magnetic field.

In electromagnetism and electronics, an electromotive force is an energy transfer to an electric circuit per unit of electric charge, measured in volts. Devices called electrical transducers to provide an emf by converting other forms of energy into electrical energy.

An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through a surface or into a control volume.

induced emf e = dphi /dt

so we need an expression for phi = BA = Bpi r^2

and since circumference C = 2 pi r,

we can write that as phi = BA = B* pi (C^22/4 pi^2 2)

phi = BC^2/ 4p

Therefore d phi /dt = (BC/2pi ) (dC/dt)

since we know C is a function of t.

after 8 seconds, the circumference is 160 - 9*15 = 25 cm.

= (0.8)(0.25/2*3.14) )(0.15)

Emf= 0.00477 V or 4.77 mV

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induced current I = emf/R (direction is clockwise)

Hence, the magnitude of the emf E is 0.0047 V and the Direction of the induced current is clockwise.

To learn more about the current and EMF the link is given below:

https://brainly.com/question/18883136?

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