This quantity is a constant for particles in the inner magnetosphere if the field varies in timescale much longer than the drift period. The phase shift in the Aharonov-Bohm effect is equal to this quantity times electric charge divided by h-bar. This quantity is equal to the MMF divided by the reluctance, according to Hopkinson's law. The derivative of this quantity with respect to charge is the (*) memristance. This quantity divided by current is equal to inductance. The integral form of Gauss’s (-5[1])law for magnetism states that this quantity is zero. The negative (-5[1])time derivative of this quantity is equal to the electric motive force according to Faraday’s law. With an SI unit called the weber, for 10 points, identify this quantity that measures the amount of magnetic field through a surface. (10[1])■END■ (10[2])