12. The square below has a side length of 10cm. Find the: a) E field strength at the centre of the square. #7NC 13. Four charges are placed in the corners of a square 40cm wide as shown. In roughly what direction is the -4pC charge being pulled? Do not calculate. -2pic 14. Consider the two changes at rest shown below, then answer the following True/False questions: -3UC O a) Positive work was done to bring the two charges together, bj If I release the charges they will accelerate toward each other. c) If I increase the distance between the charges, I increase the potential energy of the system. d) If i increase the distance between the charges, I increase the force between them. el The force on the left charge is repulsive. The force on the right charge is bigger than the force on the left charge. g) The total energy of the system is negative h) The system is bound. 15. A region has a constant electric field of 140N/C [East] going through it. i] What force would a -3.0C charge feel in this electric field? Include direction. bj What force would a + 12.OC charge feel in this field