I would appreciate it if someone could help me figure out how to answer part (b)
ID: 1696100 • Letter: I
Question
I would appreciate it if someone could help me figure out how to answer part (b) of this question. I calculated correctly the equilibrium angle in part (a) to be 4.677 degrees. Part (b)'s solution should be of relatively small magnitude and is to be reported in micro Teslas. All help would be greatly appreciated.
A simple gaussmeter for measuring horizontal magnetic fields consists of a stiff 50 cm wire that hangs from a conducting pivot so that its free end makes contact with a pool of mercury in a dish below. The mercury provides an electrical contact without constraining the movement of the wire. The wire has a mass of 5 g and conducts a current downward.
(a) What is the equilibrium angular displacement of the wire from vertical if the horizontal magnetic field is 0.04 T and the current is 0.20 A?
*(b) If the current is 20 A and a displacement from vertical of 0.5 mm can be detected for the free end, what is the horizontal magnetic field sensitivity of this gaussmeter?
Explanation / Answer
At equilibium, mgsin (theta)= ILB, sin(theta)=0.2A*0.04T*0.5m/0.005kg/9.81, Theta=4.678 deg Theta=0.001 rad=sin (theta), B=0.005kg*0.001*9.81/20A/0.0005m, B=4.905*10(-3) T= 4.905 micro Teslas