Lab 4: Magnetic Force on a Current

Lab 4 of PHYS 2C LAB

Magnetic Force on a Current

All given numbers of measured data are for your reference only. You have to correct them into the right value with significant figures if you think any of those numbers is incorrect!

DO NOT use loop SF41 and SF42!

Power Supply: C.C. i.e. Constant Current.

Multi-meter: DC Ampere, 10 A.

1. R: Regression coefficient

The Main Goal:

We are going to verify the equation of force equilibrium between the Magnetic Force and the gravitational Force, F = i L B_{magnetic field}

Later, by filling out the following data table, see how well you have measured!

THE "ERROR" TABLE

procedure

Graph

L_measured, UNIT:( )

i, UNIT:( )

Measured Slope

Measured y-intercept

%ERROR about y-intercept

%ERROR of Regression

Force vs. i

N.A.

Unit: ( )

L_measured vs. F

N.A.

Unit: ( )

For a fixed wire length: Measured Length = ( ), UNIT: ( )
Current I, SI UNIT: ( )	Mass m, UNIT: ( )	Force F, UNIT: ( )
5.0
4.0
3.0
2.0
1.0
0.0	0.0	0.0
-1.0
-2.0
-3.0
-4.0
-5.0

For a fixed current. My recommendation is 5 Amp. Current = ( ), SI UNIT: ( )
Loop	Measured L UNIT: ( )	Mass m, UNIT: ( )	Force F, UNIT: ( )

For a fixed current and length: Current = ( ), SI UNIT: ( ) Measured / Effective Length = ( ), UNIT: ( )
Number of magnets	Mass m, UNIT: ( )	Force F, UNIT: ( )	B_{Theoretical magnetic field} = F / ( i ´ L) UNIT: ( )
0
1
2
3
4
5
6

Questions on Page 25:

Graphs concerning Questions on Page25:

Question 1: Force versus Current.

Question 2-1: Force versus Length.

Question 2-2: Length versus Force.

Question 3: Force versus B-field, or Force versus Number of Magnets.

Question 1, Set your wire length fixed. Plot your data as Force versus Current i.

Are they consistent with F = i L B_{magnetic field}?
Requirement:

(0.5): In a reflection, just write "YES" or "NO", now.

(0.5): Please look at the last two columns of THE "ERROR" TABLE. You must offer at least one quantitative explanation for each slope you have. And it is better in percentage.

Question 2-1, Set your current fixed. Are your data consistent with F = i L B_{magnetic field}?

Requirement:

(0.5): In a reflection, just write "YES" or "NO", now.

(0.5): Please look at the last two columns of THE "ERROR" TABLE. You must offer at least one quantitative explanation for each slope you have. And it is better in percentage.

IN-CLASS QUIZ 2-2,The effective length of a current loop may be shorter than the total length. Use only the single sided loops to plot "L_measured versus F". Can you determine the difference between effective and measured lengths from the intercept?

Requirement:

You must tell me the mathematical equation between effective and measured lengths from the y-intercept.

(0.5): From Y = M X + B_y-intercept, write down the mathematical equation between L_measured and F entirely from all information of your GRAPH "L_measured versus F"

(0.5): From the above result, revise it as Y - B_y-intercept = M X, then write down the physical meaning of Y - B_y-intercept.

Question 3, For a fixed current and length, are the data consistent with F = i L B_{magnetic field}?

Requirement:

Graph "Force vs. Numbers of Magnets"	y-Intercept, unit: ( )	Slope, unit: ( )	Regression Coefficient
Theoretical	0	Force from a single Magnet =	1
Measured
%ERROR	N.A.	%	%

(0.5): In a reflection, just write "YES" or "NO", now.

(0.5): Please look at the above DATA TABLE. You must offer at least one quantitative explanation for each slope you have. And it is better in percentage.

Additional Question, Please write down a simple conclusion of the whole Lab 4 of Phys 2C Lab.
Requirement:

(0.5) Write it in no more than 4 sentences.

(0.5) Use some of your data tables, graphs and answered questions to make some quantitative argument.

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