-15-10 -5 BA 1.5 1 0.5 5 10 15 20 (μH×104) -0.5 -1 -1.5 FIGURE 6.29 We will examine the magnetic material with the experimental B-H curve given in Fig. 6.29 in the textbook (p. 293 – careful about the horizontal axis units). R 6 V Suppose you have a rod of this material that is 10 cm long and has a square cross-section of side a = 1 cm. You want to saturate its magnetization by wrapping loops of wire around it and sending a current through the wire. You have a 6-V battery and a choice of 1-watt resistors (you can choose any resistance R you want, but if the power dissipated in the resistor exceeds 1 W it goes up in smoke). What is the minimum number of loops that you need? (Hint: although we derived the field inside a long solenoid using cylindrical loops, square loops will not change the result all that much, so you can still use H = H₂ = nl to a very good approximation. By the way, this is pretty much what you are doing in Lab #3 to saturate your magnetic toroid).

-15-10 -5 BA 1.5 1 0.5 5 10 15 20 (μH×104) -0.5 -1 -1.5 FIGURE 6.29 We will examine the magnetic material with the experimental B-H curve given in Fig. 6.29 in the textbook (p. 293 – careful about the horizontal axis units). R 6 V Suppose you have a rod of this material that is 10 cm long and has a square cross-section of side a = 1 cm. You want to saturate its magnetization by wrapping loops of wire around it and sending a current through the wire. You have a 6-V battery and a choice of 1-watt resistors (you can choose any resistance R you want, but if the power dissipated in the resistor exceeds 1 W it goes up in smoke). What is the minimum number of loops that you need? (Hint: although we derived the field inside a long solenoid using cylindrical loops, square loops will not change the result all that much, so you can still use H = H₂ = nl to a very good approximation. By the way, this is pretty much what you are doing in Lab #3 to saturate your magnetic toroid).