Passage V
Students studied electric forces between charged spheres using the apparatus shown in Figure 1.
In each trial, the students mounted 2 uncharged conducting spheres D cm apart on the stands. Then they placed a negative charge on each sphere. The electric force between the spheres caused Stand 2's sphere to move away from Stand 1's sphere, thereby twisting the vertical wire clockwise (see Figure 2).
The students twisted the wire counterclockwise until Stand 2's sphere had moved back to its original position. The angle through which they twisted the wire,
25. The amount of charge the students initially placed on Sphere A using the charging probe was the same for all of the trials in which of the studies?
Your Answer is
Correct Answer is D
Explanation
From the 4th line of the text part of Study 1, it can be seen that the electric charge of sphere A is -7.5×10-9;
The third line of Study 2 is also displayed to A The same charge;
The third line of Study 3 shows that sphere A also has the same charge