A rod 8 cm long is uniformly charged and has a total charge of −21.8 μC. The Coulomb constant is 8.98755×10 N·m /C . Determine the magnitude of the electricfield along the axis of the rod at a point 42.279 cm from the center of the rod. Answer in units of N/C.

The magnitude of the electric field along the axis of the rod is 1.106 X 10⁶ N/C

Explanation:

The magnitude of the electric field along the axis of a rod is given as;

where;

λ is linear charge density, C/m

a is the distance from center of the rod, = (0.42279 - 0.08/2)m = 0.38279 m

L is the length of the rod,  = 0.08 m

ε is the permittivity of free space = 8.85 x 10⁻¹² C²/Nm²

λ  = Q/L = (21.8 μC)/0.08 = (21.8 * 10⁻⁶C)/0.08 = 2.725 x 10⁻⁴ C/m

1/4πε = k = 8.98755 x 10⁹ Nm²/C²

Solving for E

Therefore, the magnitude of the electric field along the axis of the rod is 1.106 X 10⁶ N/C

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it

your answer is c! hope this : )