Question

A straight, stiff, horizontal wire of length 25 cm and mass 90 g is connected to a source of emf by light, flexible leads. A magnetic field of 1.33 T is horizontal and perpendicular to the wire. Find the current necessary to float the wire, that is, find the current for which the magnetic force balances the weight of the wire.

Answer 1

Answer:2.65 A

Explanation:

Given

Length of wire $L=25\ cm$

mass of wire $m=90\ gm$

Magnetic field $B=1.33\ T$

Force on wire due to magnetic field

$F=BiL$

Force due to magnetic field will balance the weight of wire

$F=mg$

$BiL=mg$

$1.33\times i\times 0.25=0.09\times 9.8$

$i=2.65\ A$