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 (-5[1])equal to the MMF divided by the reluctance, according to Hopkinson's (15[1])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 law for magnetism states that this quantity is zero. The negative time derivative (10[1])of this quantity is equal to the electric motive force according to Faraday’s law. With an SI unit called the weber, for 10 (10[1])points, identify this quantity that measures the amount of magnetic field through a surface. ■END■ (10[1])