Φ= ∫ S B ⋅ e n dA MathType@MTEF@5@5@+=feaagCart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHXgaruavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGeaGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaqFn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpeWZqaaiqaciWacmGadaGadeaabaGaaqaaaOqaaGWaciab=z6agHWaaiab+1da9maapefabaaccmGaa0NqaaWcbaGaae4uaaqab0Gaey4kIipakiabgwSixlaa9vgadaWgaaWcbaGaaeOBaaqabaGccaqGKbGaamyqaaaa@41D3@
where endA is the vector surface element