i have searched the explanation of these terms in google..but i was still not clear about it.
i) what happens when a capacitor is connected in series and in parallel?
Assume your caps are 1uF,
Connecting two in Series, would give an overall capacitance of 0.5uF, in parallel 2uF
what is the effect of impedance on a capacitor ?is this the same as resistance?
Impedance of an ideal capacitor is a function of the frequency of the alternating voltage applied across the capacitor.
Xc = 1 / [2*pi *freq *cap)
ii) what is bleeding resistor,steering diode,current source?where and when do we need it?
A bleed resistor across the cap is used to discharge the cap when the supply voltage is switched OFF
A steering diode is used to control the direction of flow of current in a circuit.
A current source has to be defined in the context of the circuit that you are using... the question is too general.