04_23_Induction_Review

04_23_Induction_Review - Faraday’s & Lenz’z Law E =...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Today4/23 o Magnetic Induction Review o HW Questions? o Exam 4/24 o Force and motion of charged particles o B-fields due to wires o Force and Torque on current loops o Forces from currents (like 4/16 Wires 2) o Induced current (like 4/17)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Magnetic Induction o The current only flows while: o the B-field is changing o the ring is moving o the magnet is moving o It’s all about a “changing” B field!!! o Look at whether the # of field lines are increasing or decreasing
Background image of page 2
Force on Current Loops o Ch 21: Force/Torque arises from a battery operated loop in a static B-field. o Ch 22: Current in loops “induced” by a “changing” external field. The loop then reacts as in Ch 21. o In fact, battery operated loops resist the changing field caused by themselves! Called “Self Induction” see 22.8
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 4
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 6
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Faraday’s & Lenz’z Law E = - ∆ Φ ∆ t Φ is the # of field lines inside loop Lenz’s Law Loop “Voltage” Φ can change in many ways: changing B-field changing loop area changing loop angle changing B-field angle This is the “equation” you will see on the exam E = - ∆ Φ ∆ t Using o Identify initial field direction o Identify final field direction o Determine direction of the “change” o Use Lenz’s law to determine B-field due to the current induced around the loop o Use RHR #2 to find direction of induced current Energy Considerations o It takes energy to push current around a loop o Therefore, forces arising from induced currents must always serve to retard (or slow down) the object...
View Full Document

This note was uploaded on 12/21/2010 for the course PHYS Physics 21 taught by Professor Larrywatson during the Spring '08 term at North Dakota.

Page1 / 6

04_23_Induction_Review - Faraday’s & Lenz’z Law E =...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online