Solving a problem in physics section 70 point 69 electr

69. A potential difference of 1 kV is applied to the plates of a flat air condenser. The area of the plates is 50 cm2 and the distance between them is 3 mm. After disconnecting the capacitor from the voltage source, paraffin was introduced into the space between the plates (ε2 = 2). Determine: 1) the potential difference between the plates after making the dielectric; 2) the capacitance of the capacitor before and after making the dielectric; 3) the surface charge density on the plates before and after making the dielectric.