Calculating speed needed to create motional EMF of given magnitude

In summary, to create a 3.0 V motional emf along a 1.2 m-long radio antenna, you would need to drive your car at a velocity of v = dx/dt = EMF/(B*A) = 3.0 V/(B*1.2 m) where the motion of the antenna is perpendicular to the magnetic field B. This can also be calculated using the equation EMF = v*l*B, where v is the velocity, l is the length of the antenna, and B is the magnetic field.
  • #1
Linus Pauling
190
0
1. How fast would you have to drive your car to create a 3.0 V motional emf along your 1.2 m-long radio antenna? Assume that the motion of the antenna is perpendicular to B.



2. d(phi)/dt = EMF
dphi = B*A
v = dx/dt



3. I'm really not sure here. I think the length of the antenna will be dx, but I don't see how I'd get dt so solve for velocity. In a previous problem, worked out a minimum speed needed to create an EMF by using dphi = B*A = EMF*dt. But here I don't know B or A...
 
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  • #2
Nevermind, I just overlooked the simple EMF = vlB relationship.
 

Related to Calculating speed needed to create motional EMF of given magnitude

Q1: What is motional EMF?

Motional EMF, or electromagnetic force, is a phenomenon that occurs when a conductor moves through a magnetic field, resulting in the generation of an electric potential difference.

Q2: How is the speed needed to create motional EMF calculated?

The speed needed to create motional EMF can be calculated using the equation v = E/B, where v is the speed, E is the magnitude of the EMF, and B is the strength of the magnetic field.

Q3: What units are used to measure the speed needed for motional EMF?

The speed needed for motional EMF is typically measured in meters per second (m/s) or kilometers per hour (km/h).

Q4: Can the speed needed for motional EMF be negative?

Yes, the speed needed for motional EMF can be negative if the conductor is moving in the opposite direction of the magnetic field.

Q5: How does changing the magnitude of the EMF affect the required speed?

According to the equation v = E/B, increasing the magnitude of the EMF will result in a higher required speed, while decreasing the magnitude of the EMF will result in a lower required speed.

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