Three small spheres, A, B, and C, have charges with magnitudes qA, qB, and qC, respectively.The three spheres are aligned along a straight line, as shown in the figure. At the instant shown, the net force on sphere A is zero.:

1. Which of the following statements must be true of the signs of the charges?
a. Only charges qA and qB have the same sign.
b. Only charges qA and qC have the same sign.
c. Only charges qB and qC have the same sign.
d. Charges qB and qC have different signs.
e. Charges qA, qB, and qC all have the same sign.

2. The ratio qC/qB is...
a. 9/4
b. 1/1
c. 4/9
d. 1/4
e. 1/9

3. Which of the following is true about the sign of charge qA?
a. The sign of charge qA must be the same as that of qB.
b. The sign of charge qA must be the same as that of qC.
c. The sign of charge qA must be the same as that of either qB or qC greater magnitude.
d. The sign of charge qA must be the same as that of either qB or qC lesser magnitude.
e. It is possible that qA could be either positive or negative.


OFFERING A LOT OF POINTS FOR ANSWERS AND EXPLANATIONS TO ALL THREE!!