In the shown circuit involving a resistor of resistance `R Omega`, capacitor of capacitance C farad and an ideal cell of emf E volts, the capacitor is initially uncharged and the key is in position 1. At t = 0 second the key is pushed to position 2 for `t_(0) = RC` seconds and then key is pushed back to position 1 for `t_(0) = RC`seconds. This process is repeated again and again. Assume the time taken to push key from position 1 to 2 and vice verse to be negligible.
Then the variation of charge on capacitor with time is best represented by
A.
B.
C.
D.
