Derive an expression for capacitance of a parallel plate capacitor separated by dielectric medium
Answers
Derive an expression for the capacitance of a parallel plate capacitor, whose plates are separated by a dielectric medium. Answer: ... Thus a capacitor has two plates separated by a distance having equal and opposite charges.
Answer:
Capacitance or electric capacity indicates the ability of a system to store charge.
It is defined as the ratio of charge stored in the conductors to the potential difference across the conductors.
Its SI unit is Farad (F). Hence:
《C=VQ》
●To derive the expression of capacitance of parallel plate capacitor of conductor area A and distance between the conductors as d with a dielectric of dielectric constant K carrying a charge Q and potential difference V, refer to the attached figure.
●Electric field between plates of the capacitor can be found using Gauss Law.
E=Kεoσ
E=KεoAQ as σ=AQ
●Electric field is defined as the gradient of potential.
E=dV
⟹V=KεoAQd
By definition of capacitance,
C=VQ
=dKεoA