How To Recharge Loop Mobile?

Help finding induced emf, magnitude, and direction of a loop?

• A square loop of wire of side 2.3 cm and electrical resistance 79 Ω is near a long straight wire that carries a current of 7.5 A in the direction indicated. The long wire and loop both lie in the plane of the page. The left side of the loop is 9.0 cm from the wire. (a) If the loop is at rest, what is the induced emf in the loop? in nV What are the magnitude and direction of the induced current in the loop? magnitude in pA (i know the direction is no current) What are the magnitude and direction of the magnetic force on the loop? magnitude in N (i know the direction is no force) (b) Repeat if the loop is moving to the right at a constant speed of 42 cm/s. induced emf: in nV induced current: magnitude in pA ( i know direction is CW) magnetic force: magnitude in N (i konw direction is to the right to the left) (c) In (b), find the electric power dissipated in the loop. in W Calculate the rate at which an external force, pulling the loop to keep its speed constant, does work. in W

• Answer:

  (a) 0 nV induced emf requires change in magnetic field produced by the current in the long wire.