LC circuit

[mahlon]

;) Hi, I supposing i connected a capacitor and an inductor in parallel across a 240V 50Hz socket, would the circuit short circuit if i don't include a resistor. Because i was told that a resistor must be present to act as a load since the capacitor and the inductor have zero power consumption.

[walid]

this depends on the values of L and C.
the primary coil of the stepdown transformer is connected to 230V AC
Cap rating 230v or more can be connected across 230v
tell us what u want to do to be able to understand

[mahlon]

Hi , thanx walid for your effort to reply

Ok basically i am studying resonance. I am attempting to connect a non-polar 2.2 uf 250 V capacitor in parallel with a 4.6H coil. I want to connect it to a socket which supplies 240V 50Hz ac. My question to you is, will the circuit short circuit if i don't include a resistor? From what i was told that when it comes to using mains voltage there has to be some resistance or load otherwise there will be a short circuit,

[Kain]

Connecting a stright wire and an inductor is not the same thing. A wire has some ammount of inductance but it is very small on first place. Another thing to consider is that every wire that you get your hands on has some resistance - it's a resistance derived from the resistivity of the material and the longer the wire is the more resistance you will have. The primary coil of a step down transformer has higher resistance than the secondary as well and thus limits the current through the coil (coils are made of wire too). If you hook up a short wire stright into the plug between the phase and neutral then you short it 100% since this wire has very small resistance (you most likely blew your fuse  ;D). I would recommend you to use low voltage sin wave generator for resonance experiments - it's less dangerous and it has built in current limiter and so on, so there is no chance of you blowing yourself up or blowing the coil up or something else  ;D. Capacitors are dead short at the first moment (this is for very short ammount of time) this is why people tell you that you need to hook up a series resistance. The series resistance will limit down the very high inrush current in the very beginning when you connect the LC circuit. 

[Kain]

One more thing - I recommend you to experiment first with transient responces of RC and RL circuits so you can notice few things, sich as inductors are dead short to DC once they build their magnetic field and capacitors act as nearly open circuit once they charge up.
Cheers  :)

[bloki]

You may connect 4.6H inductor if it can withstand at least 200mA current and 2.2uF/250Vrms (rms not DC, DC rating should be 630V)capacitor parallely to mains voltage.