question_answer

Three capacitors, each of \[3\mu F,\]are provided. These cannot be combined to provide the resultant capacitance of:   [JEE Main Online Paper ( Held On 09 Apirl  2014  )

A) \[1\mu F\]                                         

B) \[2\mu F\]

C) \[4.5\mu F\]                      

D) \[6\mu F\]

Correct Answer: D

Solution :

                Possible combination of capacitors (i) Three capacitors in series combination \[\frac{1}{{{C}_{eq}}}=\frac{1}{3}+\frac{1}{3}+\frac{1}{3}\]\[\therefore \]\[\frac{1}{{{C}_{eq}}}=1\mu F\] (ii) Three capacitors in parallel combination \[{{C}_{eq}}=3+3+3=9\mu F\] (iii) Two capacitors in parallel and one is in series \[{{C}_{eq}}=2\mu F\] Two capacitors in series and one is in parallel \[{{C}_{eq}}=4.5\mu F\]