PHYS 102 Chapter Notes - Chapter 29: Voltage, Line Integral, Charged Particle

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blackgiraffe178

19 Mar 2017

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Document Summary

An electromotive force is required for a current to flow in a circuit. For most devices that plug into a wall socket, the source of emf is not a battery but an electric generating station. Electromagnetic induction: if the magnetic flux through a circuit changes, an emf and a current are induced in the circuit. Ce(cid:374)t(cid:396)al p(cid:396)i(cid:374)(cid:272)iple of ele(cid:272)t(cid:396)o(cid:373)ag(cid:374)eti(cid:272) i(cid:374)du(cid:272)tio(cid:374) is fa(cid:396)ada(cid:455)"s la(cid:449). Relates i(cid:374)du(cid:272)ed e(cid:373)f to (cid:272)ha(cid:374)gi(cid:374)g magnetic flux in any loop, including a closed circuit, Le(cid:374)z"s la(cid:449) helps to p(cid:396)edi(cid:272)t the di(cid:396)e(cid:272)tio(cid:374)s of i(cid:374)du(cid:272)ed e(cid:373)fs a(cid:374)d (cid:272)u(cid:396)(cid:396)e(cid:374)ts. Ma(cid:454)(cid:449)ell"s equations describe the behavior of electric and magnetic fields in general. If magnet is stationary and coil is moved, there is current during the motion: called an induced current, corresponding emf required to cause this current is an induced emf. When there is no current in the electromagnet, so that b = 0, the galvanometer shows no current.

Related Questions

Faraday's law of induction deals with how a magnetic flux induces an emf in a circuit. Recall that magnetic flux depends on magnetic field strength and the effective area the field is passing through. We'll start our investigation by looking at the field strength around a bar magnet.
Position the magnet around the coil so that the region labeled A in the figure below is inside the coil. Move the magnet slowly back and forth and observe the effect on the brightness of the bulb and the needle of the voltmeter. Repeat the same process for the other two regions.

For which of the regions shown in the figure is the observed effect the strongest?

turquoiseeel224

Please answer either True or false and explain.

1. A large magnetic flux change through a coil must induce agreater emf in this coil than a small flux change.

2. A circular metal loop surrounds an ideal solenoid such that theplane of the loop is perpendicular to the cylindrical axis of thesolenoid. If the current in the solenoid is steadily increased, noemf is induced in the loop because the magnetic field outside anideal solenoid is zero.

3. When it is connected in a circuit, an inductor must resisthaving current flow through it.

Please explain, thanks

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 × 10^{−6 s.}

(Hint: Recall from Topic 19 that the magnetic field at the center of the current-carrying external coil is