Electromagnetism Flashcards
What is a magnetic field?
It is the region of space where a magnetic pole, moving charged particle or current-carrying conductor will experience a magnetic force.
definition of magnetic flux density?
It is defined as the force per unit current per unit length acting on an infinitely long current-carrying conductor placed perpendicularly to the magnetic field.
!! unit is the Tesla (T)
What must you bring to exam when drawing concentric circles?
yes u must bring a COMPASS pls i swear wn not gonna remind
What is the formulas for the magnetic flux densities?
scam question! no one really cares because its on the formula sheet lmao just know what the different letters mean
N is the number of turns
n is the number of turns per unit length (i.e. N/L)
What is the formula for the force acting on a straight current-carrying conductor?
F = BILsinθ
!! θ is the angle between the current and the magnetic field !! (wn tip: look at the arrowheads i think oops forgot)
Conductors carrying currents in which direction will attract? (same or opposite)
same direction -> attract
opposite direction -> repel
(ironically the opposite of a magnet)
What is the formula for the force acting on a moving charged particle?
F = Bqvsinθ
!! for a moving electron / negatively charged particle, the conventional current is in the opposite direction of its motion !! <– impt in EMI
An electron enters a region of a magnetic field B. Explain why it goes into a helical motion.
(btw it can only happen if the electron enters in at an angle)
When the electron enters in at angle θ, there is a horizontal component to the velocity and therefore the electron will more in a direction parallel to the magnetic field. The magnetic field also acts a magnetic force normal to the electron and will therefore move in a circular motion.
What is the criteria for a charge to make a full revolution in a magnetic field?
The charge must start moving inside the magnetic field.
