The question is this:
"Design an experiment to measure the mass per unit length n of a length of copper wire. The wire will be placed in an external uniform magnetic field and I will have a variable power supply"
- set of slotted masses
- bare copper wire
- AC ammeter
- variable AC power supply
- uniform magnetic field setup
- other equipment normally available in a lab...
- Observations (what are you going to measure?)
- Analysis (how are you going to use what you measure?)
- Any other good points
Before this, we had to find an expression for the speed of a stationary wave in terms of n (mass per unit length) and T (the tension in the wire) which came out to be:
c= squared root of (T/n)
we then considered a conductor (with current I) in an external magnetic field... F= BIL ... if the current is alternating in the wire, the force would alternate upwards and forwards.
If the wire is fixed at both ends, a stationary wave is formed. Hence we can measure the wavelength for the stationary wave.
ANYONE CAN GIVE ME SOME HELP?? THANK YOU!!!
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A2 Design Experiment question.. HELP!! watch
- Thread Starter
- 12-10-2006 18:40
- 13-10-2006 11:58
Adjust length so get a standing wave with Annitmode in middle and nodes at each end.
c = f x lambda.
f is 50 Hz if using mains based PSU. Resonance. Driving freq = natural freq of wire.
c = your expression
lambda / 2 = distance between 2 nodes on a standing wave.
Should be enough there to work out n.
- 18-10-2006 17:58
This would be a fine xperiment for our designing paper 2mrw;D