# Loop in a non-uniform magnetic field with downward force

Imagine a circular wire loop of radius R carrying current I, suspended above a current carrying solenoid in the non-uniform magnetic field of the solenoid. Here, $\vec{B}$ has a radial component as the magnetic field, to a good approximation, radiates spherically.

It is claimed there is a downward force on the loop.

Why is this so? What is happening?

• The 'suspended loop' is depicted with the letter "I" and an arrow. Why? Also, you speak of 'nonuniform magnetic field'; could this be a time-dependent (changing) magnetic field? – Whit3rd Sep 2 '16 at 1:02
• @Whit3rd Page 273 117.55.241.6/library/E-Books/… – Physkid Sep 2 '16 at 1:17