Solving a problem in physics section 67 point 78 electr

78. In the circuit (see figure), the electrostatic field strength in a flat capacitor is E = 2 kV / m, the external resistance is R = 5 Ohms, the internal resistance of the emf source is r = 1 Ohms, the distance between the capacitor plates is d = 0.1 cm. Determine EMF of a current source.