Asmall glass bead charged to 4.0 nc is in the plane that bisects a thin, uniformly charged, 10-cm-long glass rod and is 4.0 cm from the rod's center. the bead is repelled from the rod with a force of 940 μn. what is the total charge on the rod?

The total charge on the rod at the given electric field strength is .

The given parameters;

The electric field due to the total charge on the rod is calculated as follows;

The force experienced by the charged bead is calculated as;

Thus, the total charge on the rod at the given electric field strength is .

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Explanation:

Electric field due to a finite wire at some distance "x" from it on its perpendicular bisector is given by the formula

so here we will have

now we know that

F = qE

we will have

so we will have

so total charge on the rod is given as

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.

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