# How the total energy of a $LC$ oscillator remains unchanged while placing a coil near the inductor of the $LC$ oscillator?

If the capacitor is initially charged with $$Q$$ charge and then connected to a inductor then discharging takes place and the energy stored in electric field gets converted into the energy stored in magnetic field. Energy of a $$LC$$ oscillator oscillates in the electric field of capacitor and magnetic field of inductor and the energy remains unchanged for ideal case.

Now if we placed a coil near the inductor then with the changing of current magnetic flux associated with the coil also changes and that causes an EMF in the coil and if there is resistance of $$R$$ with the coil then there is some loss of energy but the energy in $$LC$$ oscillator remains unchanged.

Where from the energy comes that is lost in the coil?

• Why do you say the energy of the LC oscillator remains unchanged? Wouldn't it make sense that it is the oscillator's energy that is slowly being lost through dissipation? Commented Jan 5, 2020 at 17:59
• I am considering an ideal oscillator. Commented Jan 5, 2020 at 18:13
• You don't say whether the coil is open-circuit, short-circuited or connected to something else. If the coil is open circuit there will be no energy dissipation in it. Commented Jan 6, 2020 at 0:04
• No. I mentioned there is a resistance of R. I just wants to know where from the energy comes that is used in the LR ciruit as the energy stored in the LC oscillator remains unchanged. Commented Jan 6, 2020 at 2:02