section 2: magnetic induction
DESCRIPTION
Section 2: Magnetic Induction. Magnetic Field Around a Wire Right Hand Rule: Current is in the direction of positive charge flow. Magnetic Fields around Paired Wires. Magnetic Field in a Loop:. Magnetic Field in Solenoid. Electro Magnet. How it works: What makes a strong electromagnet: - PowerPoint PPT PresentationTRANSCRIPT
Section 2: Magnetic Induction
Magnetic Field Around a WireRight Hand Rule:
Current is in the direction of positive charge flow
Magnetic Fields around Paired Wires
Magnetic Field in a Loop:
Magnetic Field in Solenoid
Electro Magnet
How it works:
What makes a strong electromagnet:1) 2) 3)
Forces on charges:
To find the force:1) Fingers go in the direction of the
field2) Thumb goes in the direction of
the charge3) Palm goes in the direction of
force of a (+) charge and opposite for (-) charge.
Force, Current, and Magnetic FieldsForce on a positive charged particle moving througha magnetic field: F = BqV
Sample Problem: Find the force and direction on a 2C positive charge that is in a 3 T (Tesla) magnetic field and traveling with a velocity of .5m/s
Force on a wire with current in a magnetic field: F = BIL
Sample Problem: Find the force on the 1.5 meter wire that has 2 amps of current passing through it when placed in a 10 T (Tesla) magnetic field.
Electromagnetic Induction: When current is created in a conductor using a changing magnetic field
Factors that affect magnetic induction:1) 2)
Lenz’s Law: The direction of the magnetic field of an induced current oppose the magnetic field that created it.
Faraday’s Law for creating current: Voltage = -NA(ΔB/Δt)
Sample Problem: Find the voltage produced when a coil of wire with 5 turns and a cross section of .002m2 feels a magnetic field change of .4T/s.
Practice Problems
A 52 turn coil with an area of .0055m2 is dropped from a position where the magnetic field strength is zero to a position where the field strength is .55T which occurs in .25s. Find the average emf (induced voltage).
Building an Electric Motor