Question 45 of 180

Two equal capacitors are first connected in series and then in parallel. The ratio of the equivalent capacities in the two cases will be:

A$1:2$B$1:4$C$4:1$D$2:1$

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Answer: (B) $1:4$

For series combination,

$\dfrac{1}{{C}_{e{q}_{1}}}=\dfrac{1}{C}+\dfrac{1}{C}\Rightarrow {C}_{e{q}_{1}}=\dfrac{C}{2}$
For parallel combination,

${C}_{e{q}_{2}}=C+C\Rightarrow {C}_{e{q}_{2}}=2C$
$\Rightarrow \dfrac{{C}_{e{q}_{1}}}{{C}_{e{q}_{2}}}=\dfrac{\left(C/2\right)}{2C}=\dfrac{1}{4}=1:4$

JEE Main Physics practice question on Capacitors (Grouping of capacitors), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.