Q.

A parallel plate capacitor has plate area 40 cm2 and plate separation 2 mm. The space between the plates is filled with a dielectric medium of thickness 1 mm and dielectric constant 5. The capacitance of the system is              [2023]

1 103ε0 F  
2 310ε0 F  
3 24ε0 F  
4 10ε0 F  

Ans.

(1)

A=40×10-4 m2=4×10-3 m2

d=2×10-3 m, k=5, t=10-3 m, C=?

C=ε0Ad-t+tk=ε0×4×10-3(2-1)×10-3+10-35=4ε0×56=10ε03 F