Question 87 of 180

Two capacitors, each having capacitance $40\mu F$ are connected in series. The space between one of the capacitors is filled with dielectric material of dielectric constant $K$ such that the equivalence capacitance of the system became $24\mu F$. The value of $K$ will be :

A$1.5$B$2.5$C$1.2$D$3$

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Answer: (A) $1.5$

When a dielectric is inserted between the sheets of a capacitor, its capacitance becomes $KC$.
Now the equivalent capacitance in series combination will be,
${C}_{eq}=\dfrac{C\times KC}{C\left(1+K\right)} \Rightarrow 24=\dfrac{40K}{1+K} \Rightarrow K=1.5$