Which happens to the magnetic field of a wire when you change the direction of the current in the wire?

Magnetic field due to along straight wire is given by the formula

here we know that

r = distance of the point from the wire

i = current in the wire

so here we also know that direction of magnetic field due to current carrying wire is given by using right hand thumb rule as per this rule if we put our thumb in the direction of current then curl of our fingers will show the direction of magnetic field around the wire

So here if we change the direction of current in the wire then the magnetic field direction will also get reversed while the magnitude will remain unchanged

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s