At a distance of 0.75 meters from its center, a van der graff generator interacts as if it were a point charge, with that charge concentrated at its center. a test charge at that distance experiences an electric field of 4.5 × 105 newtons/coulomb. what is the magnitude of charge on this van der graff generator?

a. 1.7 × 10ˆ-7 coulombs
b. 2.8 × 10ˆ-7 coulombs
c. 3.0 × 10ˆ-7 coulombs
d. 8.5 × 10ˆ-7 coulombs

Currents in dc transmission lines can be 100 a or higher. some people are concerned that the electromagnetic fields from such lines near their homes could pose health dangers. for a line that has current 150 a and a height of 8.0 m above the ground, what magnetic field does the line produce at ground level? express your answer in teslas and as a percentage of the earth’s magnetic field, which is 0.50 g. is this value cause for worry?