Answer code to Fall 2003 second midterm


1.  1.6
2.  1.922 x 10^-27 Cm
3.  8.847 x 19^-6 C
16. (a) I > 5.35A
17. (e) r_a = (1/2) r_b
18  (e) about 1/2 a cent (0.529c)
19.  (c) R= 4 Ohms 
20.   (b) halved. R0 = 3 Ohm  R'= 1.5 Ohm
21.  (a) 6V
22.  (d) helix
23.  (c) 1.6 x 10^-12 in x direction
24.  (c) 0.753 Nm
25.  (b) negative x direction (unlike currents repel)
26.  (d) 6.7mT
27.  (e) The field produces a max torque when it is in the plane of the coil.