The figure shows a positive charge placed in a uniform electric field. is the force exerted on the +1 c charge directed up or down?

DOWN

Explanation:

When a positive charge is placed in uniform or nonuniform electric field then due to the Electric field present in that region the charge will experience electrostatic force on itself.

This electrostatic force is given as

here we know

q = charge

E = electric field

Now if charge is positive then force on the charge is always in the direction of electric field but if charge is negative then force is exactly opposite to electric field direction.

So here it will have force in the direction of electric field which is DOWN

0.11 m/s and 0.28 m/s should be correct

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it