Answer:
1. The voltage decreases because of the insertion of the Teflon.
Explanation:
When we placed the dielectric medium/material between the plates of the capacitor. It increases the capacitance. Increase in capacitance means that the electric field between the plates will decrease and thus there will be a decrease in voltage. As we know that the capacitance has an inverse relation with the electric field between the plates. Mathematically,
[tex]q = CV\\C = Q/V[/tex]
where C is capacitance, V is Voltage and q is a charge.
By putting "Teflon between the plates of capacitor there will be a decrease in voltage."