# current induced in magnetic field

"If a wire loop is completely in magnetic field no current is induced as voltage induced is balanced by an equal and opposite voltage. "

My guess for this statement is that the loop wire must be stationary and that voltage is zero if its equal on both sides of the wire my question is if current will stil be induced if the wire loop is moving but is still completely in the magnetic field. (I know how as it enters and leaves induced current moves either clockwise or anti so what wil happen if its moving but not entering or leaving)

• If it moving in a uniform magnetic field, no current will flow as the magnetic flux through the wire loop is constant and therefore, the net induced EMF is zero.($\int_{loop} \vec E \cdot \vec {dl}=-d\phi /dt$) But if it moves in a non-uniform field, there may be a current in the loop. – Satwik Pasani Sep 24 '13 at 12:12
• @SatwikPasani If it moves in a non-uniform field, there can be an EMF, however the EMF will be equal to $\oint_{loop}\vec{f}_m\cdot d\vec{\ell}$ where $\vec{f}_s$ is the magnetic force per unit charge. The EMF of $\oint_{loop}\vec{E}\cdot d\vec{\ell}$ is actually equal to the negative of the instantaneous flux of the change of the $\vec{B}$ field, $-\iint \frac{\partial \vec{B}}{\partial t}\cdot d\vec{a}$. – Timaeus Feb 12 '15 at 2:33