Question

Two parallel plate air capacitors are constructed,one by a pair of iron plates and the second by a pair of copper plates of same area and same spacings. Then:

• A. the copper plate capacitor has a greater capacitance than the iron one
• B. both capacitors will have equal non zero capacitances, in the uncharged state
• C. both capacitors will have equal capacitances only if they are charged equally
• D. the capacitances of the two capacitors are unequal even they are unequally charged

Answer 1

The correct option is B both capacitors will have equal non zero capacitances, in the uncharged state

We know that the capacitance of a capacitor $=\frac{ϵA}{d}$

where, $ϵ=$ Permiittivity of the dielectrics material used between the plates.

$A=$ Area of the plates

$d=$ Distance between the plates

Since, the capacitance does not depend on the metal of plates,both capacitors will have equal non zero capacitances, in the uncharged state

Therefore, B is correct option.