tbomb
04-19-2011, 05:26 PM
A circuit consists of a flashlight bulb, rated 3.0V/1.5W, and ideal wires with no resistance. The right wire of the circuit, which is 10cm long, pulled at constant speed v through a perpendicular magnetic field of strength 0.10T.
What speed must the wire have to light the bulb to full
brightness?
-Using, I=vLB/R and P=(V^2*L^2*B^2)/R
v= velocity L=length B=magnetic field R=resistance V=potential
-Then v= sqrt((P*R)/(L^2*B^2)) <- would be used for solution, but R is needed
-So, I=P/ΔV and R= ΔV/I, where P=power
Now, R=6ohms
When i plug numbers in a get a solution of v=300m/s.
Does this seem right? Dont have answers, and 300m/s seems really fast.
What speed must the wire have to light the bulb to full
brightness?
-Using, I=vLB/R and P=(V^2*L^2*B^2)/R
v= velocity L=length B=magnetic field R=resistance V=potential
-Then v= sqrt((P*R)/(L^2*B^2)) <- would be used for solution, but R is needed
-So, I=P/ΔV and R= ΔV/I, where P=power
Now, R=6ohms
When i plug numbers in a get a solution of v=300m/s.
Does this seem right? Dont have answers, and 300m/s seems really fast.