What is the direction of the magnetic force on the current in each of the six cases?

is the equation for magnetic force on a length l of wire carrying a current I in a uniform magnetic field B, as shown in Figure 2. If we divide both sides of this expression by l, we find that the magnetic force per unit length of wire in a uniform field is F l=IBsinθ.

Explanation:

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

this is poiselle's equation from fluid mechanic in physics. mech eng