a) Two charges, Q1 and Q2 are separated by distance r. State Coulomb's law and write down the force each charge. Explain the condition for a repulsive force and for an attractive force.
b) What is the magnitude and direction of the force between two charges of -10µC and + 40 µC set 100 mm apart? Comment on your answer.
Sketch the E-field and equipotentials associated with this charge system.
c) Charges of Q1 = -10 pC and Q2 = -20 pC are placed 200 mm apart.
At what point the force on a test charge of 1 C be zero?
1 pC = 10-12C. The constant = 9 x 109 m/F, where ε 0 is the permittivity of free space. ε0= 8.85 x 10-12 C2 /N.m2