phys (0301) - M&G: DC motor

split ring commutator.

an important term, remember it. it's the part of a DC motor that changes the direction of the current. other important parts include:

power source (battery)
brushes (made of carbon)
magnet
coil

having concave magnets also is better than having just plain straight magnets because there's a wider spread of magnetic field, thus a smoother turning motor.

we did learn a new formula today, it goes:

T = nBIAcos@

where:

T = torque
n = number of turns (loops of the wire in the coil basically)
B = strength of magnetic field in teslas (T)
A = area in m^2
cos@ = angle between plane of coil and the magnetic field. it becomes cos now since it is equal to 1 when the coil is perpendicular to the field

double check whether its perpendicular or parallel..