Present Remotely

Send the link below via email or IM

• Invited audience members will follow you as you navigate and present
• People invited to a presentation do not need a Prezi account
• This link expires 10 minutes after you close the presentation

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

An investigation on linearity relation of magnetic torque as

No description
by

Kai Ming Hew

on 14 April 2014

Report abuse

Transcript of An investigation on linearity relation of magnetic torque as

Introduction
Experiment
Experimental Setup
An investigation on linearity relation of magnetic torque as a function of magnetic field strength, magnetic moment and angle between magnetic field and magnetic moment in a uniform magnetic field
Magnetic Moment
Presented by
Hew Kai Ming
A0098123E
Magnetic field mapping on the surface of a spherical magnet using iron needles
Applications
Electromagnetic Induction
James Clerk
Maxwell
Maxwell's equations
Theory
(1) Torsion Dynamometer; (2) Helmholtz Coil; (3) Conductor loop; (4) Multimeter (Helmholtz Coil's Current); (5) Constanter (power source for Helmholtz Coil);
(6) Multimeter （Conductor loop's current);
(7) Power supply (power source for conductor loop)
Conductor loops with different diameters and number of turns
Vernier Calipers
- measure the diameter of loops
α = 90 degree
α = 0 degree
Conclusion
References
T vs I'
T vs I
T vs n
T vs d
2
T vs sin(α)
Definition of Magnetic Moment
Magnetic Torque
Newtonian Torque
Biot-Savart Law
=
Sources of Uncertainties

- Some of the holders of the conductor loops (especially the 3-turns one) have melted as a result of subjected to high temperature due to the dissipated heat as current passes through the conductor.

- It is suspected those insulated impurities somehow are incorporated into the conductor, and slightly changing its property, i.e. conductivity.
Uneven diameter of Conductor loops
- A fluctuation up to 4mm is realized for the data collected.

- Minimized by making 3 measurements for each conductor used and then calculating the average diameter.

- In T vs n case, however, the areas are assumed to be the same and this may not be true.
Precision & Accuracy
Precision
- From the
- From the product description " 3.5mT at 5A", the theoretical value of the constant c is 0.000700 .

- The experimental value is 0.000709 .

- The percentage discrepancy of average c is 1.36%. Max % discrepancy is 4.37% (T vs n), while min. is 0.75% (T vs sin(α)).

- The result can be considered precise.
Accuracy
- The percentage uncertainty of the average c is 1.15%.

- The max. % uncertainty is 7.42% (T vs n), while the min. one is 0.67% (T vs I').

- Besides the two currents cases, all have exceeded 5%.

- The results are not very accurate.
Images
Electrical motor:

Fan:

Magnetic Moment: