Combination fo two identical capacitors, a resistor `R` and a dc voltage source of voltage `6V` is used in an experiment on a `(C-R)` circuit. It is found that for a parallel combination of the capacitor the time in which the voltage of the fully charged combinatiomn reduces to half its original voltage is `10` second. For series combination the time needed for reducing teh voltage of the fully charged series combination by half is-

Options

A. 20 second
B. 10 second
C. 5 second
D. 2.5 second

Answer

D

Explanation

Coil A must be carrying a constant current in counter clockwise direction. That is why when A moves towards B, current induced in B is in counter clockwise direction, as per Lenz's law. The current in B in would stop when A stops moving. Choice (d) is cor