Question

Review. In studies of the possibility of migrating birds using the Earth's magnetic field for navigation birds have been fitted with coils as "caps" and "col- lars” as shown in Figure P30.1. (a) If the identical coils have radii of 1.20 cm and are 2.20 cm apart, with 50 turns of wire apiece, what current should they both carry to produce a magnetic field of 4.50 X 10-5T halfway between them? (b) If the resistance of each coil is 210 12, what voltage should the battery supply- ing each coil have? (c) What power is delivered to each coil

Can you please explain in detail how to derive the equation to use

Answer 1

4.6 BO Total distance between the axis of the coils = 4.6 cm. current has to be opposite to each other to add up. we know mognetic field due to current carrying wire B = Mol at a distance R. 2TR Don In this case B = 4.5x10-5 - 50x Mox I Tx 2.3 x 10-2 & 4.5x100 - 50% 47 x 17 x 1. π X 2.3 xor = I= 0.05 A. current through the coils should be 0.05 A. b) From ohn's low - N=IR 59 V = 0.05 x 210 Volt = 10.5 volt a 10.5 volt has to be applied.

6) me know power p=vt. =1005x 0.05 NA = 0.525 V.A or watt.