Question

Please briefly explain if possible like the process. Thank you.

1. Two small, charged plastic balls (yo can consider them to be point charges) are in a test u tube, one vertically above the other as shown in the figure below. The balls are in equilibrium a distance d apart. If the charge on one of the balls is halved, the distance between the balls in the test tube would become A. 2d B. d/2 C. v2d D. d/v2 2. Two positive 2.0 uC point charges are placed as shown in the figure below. The distance from each charge to the point P is 0.040 m. Then the charges are rearranged as shown in part (b) of the figure below. Which statement is now true concerning E and Vat point P? (V 0 at infinity.) 2.0uc 0,040 m 0040 m. 0.040 m 0.040 m 2.0 HC 2.0 HC 2.0 HC (b)

Answer 1

Equilibrium is established when the electric force between the balls = weight of upper ball .. this force is constant at any spacing.

F = k.q1.q2 / d² .. .. For constant F .. q1.q2 ∝ d² .. .. d ∝ √(q1.q2)

When q1 halved .. (q1.q2) decrease by a factor of 2 .. and d by a factor √1/2 = 1/√2

Ans .. ►(d) d/√2

E is vector

V is scalar

C. is true