The current flows from A to B in a straight wire as shown in figure and it is decreasing with time. The induced current in loop placed near to it ____

Explanation

1. Force on PQ wire which is held in air by 25 A current carrying wire which balanced with weight force of same wire PQ.
2. Magnetic field at h distance due to 25 A current carrying wire,
`B=(mu_(0)I)/(2pih)" "...(1)`
3. Small wire place in this magnetic field, magnetic force on that wire is given by,
`vecF=vec(Il)xxvecB`
`thereforeF=BIlsintheta`
`thereforeF=BIl`
`thereforeF=Il((mu_(0)I)/(2pih))`
`thereforeF=((mu_(0)I^(2)l)/(2pih))" "...(2)`
4. Currents are in opposite direction from both of wires so force on wire PQ is in upward direction.
5. Wire is displace by .h. till weight force mg balances by this magnetic force,
`thereforemg=(mu_(0)I^(2)l)/(2pih)`
`h=(mu_(0)I^(2)l)/(2pimg)`
`h=((4pixx10^(-7))xx(25)^(2)xx1)/((2pi)xx(2.5xx10^(-3))(9.8))`
`h=51xx10^(-4)`
h = 0.51 cm
I = 25 A
l = 1 m
m = 2.5 g
= `2.5xx10^(-3)`kg
`g=9.8ms^(-2)`