- #1
gillgill
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1. A simple generator has a 200-loop square coil 25.0cm on a side. How fast must it turn in a 0.550T field to produce a 120V peak output?
area=(0.25)^2
=6.25x10^-2
E=-N(BA)/t
t=-(300)(6.25x10^-2)(0-0.550T)/120V
t=8.6x10^-2 s
do you need to times it by 4 to get the time for one rotation??
2. A motor has an armature resistance of 3.40ohms. If it draws 8.70A when running at full speed and connected to a 120V line, how large is the counter emf?
V-Ir-Emf=0
Emf=V-Ir
=120-(8.7)(3.4)
=90.4V
Is this right?
3. A 30cm diameter coil consists of 30 turns of circular copper wire 2.8mm in diameter. A uniform magnetic field, perpendicular to the plane of the coil, changes at a rate of 8.65x10^-3T/s. Determine the current in the loop.
I have no idea how to start this question.
Plz help...thx...
area=(0.25)^2
=6.25x10^-2
E=-N(BA)/t
t=-(300)(6.25x10^-2)(0-0.550T)/120V
t=8.6x10^-2 s
do you need to times it by 4 to get the time for one rotation??
2. A motor has an armature resistance of 3.40ohms. If it draws 8.70A when running at full speed and connected to a 120V line, how large is the counter emf?
V-Ir-Emf=0
Emf=V-Ir
=120-(8.7)(3.4)
=90.4V
Is this right?
3. A 30cm diameter coil consists of 30 turns of circular copper wire 2.8mm in diameter. A uniform magnetic field, perpendicular to the plane of the coil, changes at a rate of 8.65x10^-3T/s. Determine the current in the loop.
I have no idea how to start this question.
Plz help...thx...