MHT CET2017PhysicsCapacitance
Two parallel plate air capacitors of the same capacity C are connected in series to a battery of emf E . Then one of the capacitors is completely filled with the dielectric material of constant K . The change in the effective capacitance of the series combination is
Options
- AC 2 K - 1 K + 1
- BC 4 K - 1 K + 1
- CC 2 K + 1 K - 1
- DC 2 K - 1 K + 1 2
Correct answer
A. C 2 K - 1 K + 1
Step-by-step solution
1 C 1 = 1 C + 1 C = 2 C ⇒ C 1 = C 2 1 C 2 = 1 C + 1 K C 1 C 2 = 1 C 1 + 1 K ∴ C 2 = C 1 + 1 K = C K ( K + 1 ) ∆ C = C K ( K + 1 ) - C 2 = C K K + 1 - 1 2 = C 2 K - K - 1 2 ( K + 1 ) = C 2 K - 1 K + 1