(b) Under what condition is the wire able to move upward at constant velocity? (c) Find the magnitude and direction of the minimum magnetic field required to move the wire at constant speed. magnitude direction ---Select--- T (d) What happens if the magnetic field exceeds this minimum value?

For the circuit shown in Fig. Q2(b), assuming the switch has been opened for a very long time, when the switch opens at t=0 s, sketch v₁ (t) and i, (t) 27 V S iL + VL - L → 158 mH 3.5 mA Fig. Q2(b) 6.6 ΚΩ www R

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Check your Understanding Repeat the calculations from the previous example for I0=0.040A .

(a) The figure below shows two parallel conducting rails 11.6 cm apart, connected by a resistor with resistance R, = 5.00 n. Two metal rods with resistances R, = 13.0 0 and R., = 15.0 0 slide along the rails with negligible friction. Rod R, slides to the left at constant speed v, = 4.00 m/s, vwhile rod R, slides at speed v, = 2.00 m/s. The rods and rails are in the presence of a uniform magnetic field pointing into the page, perpendicular to the plane of the rails, with a magnitude of B = 0.0100 T. in X2x x x * Ry x R, What are the magnitude (in µA) and direction of the current through resistor R,? 278 What are the two motional emfs? What are their directions, based on the velocities of the rods and the direction of the field? From this, can you construct a circuit diagram that allows you to apply Kirchhoff's laws? Can you use Kirchhoff's laws to set up a system of equations that allows you to solve for the current through R,? Be careful of magnitude signs. HA direction upward (b) What…

Given a current J = 0.5r-¹e-10¹t A/m², determine p、(r, t) by integrating V J (making sure på → 0 as t → ∞o).

(d) an extension cord having a 0.06 resistance and through which 4.5 A is flowing; P= W (e) a cheaper cord utilizing thinner wire and with a resistance of 0.35 Q.; P= W (f) Which extension cord dissipates more power? O The more expensive thicker power cord O The cheaper thinner power cord

ceiling. The weight comes to rest in its equilibrium position, thereby stretching the spring 2 feet. 2-pound weight is attached to the lower end of a coil spring suspended from the 0. No he weight is then pulled down 6 inches below its equilibrium position and released at t= external forces are present; but the resistance of the medium is numerically equal to 10 (axrat), where dx/dt is the instantaneous velocity in feet per second. Determine the resulting motion of the weight on the spring.

(a) — (b) — (c) O O Od>c>b> a Ob>d>a> c (d) — Ø The figure shows four arrangements in which long, parallel, equally spaced wires carry equal currents directly into or out of the page. Rank the arrangements according to the magnitude of the net force on the central wire due to the currents in the other wires, greatest first. Od>b>c> a Ob>a>c>d Ob>d>c> a & Ⓡ Ⓡ O

*35 Each of the eight conduc- tors in Fig. 29-60 carries 2.0 A