#### Question: Define the term ‘Resonance’ as applicable to a simple RLC series circuit. Discuss briefly the effect of Resonance on circuit performance. OR Explain resonance condition RLC parallel circuit.

**Q: what is resonance in electrical circuits?**

**Series resonance**

**A series circuit** is said to be at **electrical resonance **when its net reactance is zero. The frequency (F_{r}) at which **electrical resonance **occurs is called **Resonant frequency** ( F_{r}).

**Resonance conditions for series circuit**

- Impedance of
**resonance**is only resistance i.e Z=R

- Net reactance is zero

therefore, X =X_{L} – X_{c } = 0

X_{L = }X_{c}

- V
_{L }-V_{c }= 0

V_{L }= V_{c}

- Maximum current i.e line current, Imax = V/R
- The phase angle at
**electrical****resonance**is zero. - Therefore,power factor is unity (cos 0 = 1 )
- X
_{L }=X_{C}

f_{r} =

**Quality factor (Q factor)**:

**The resonance condition in RLC Parallel circuit**

**Current in AC series RLC circuit at electrical resonance**

The net reactance in **RLC circuit** shown in figure is,

If for same frequency of the applied voltage X_{L} = X_{C} (in magnitude) then X = 0 and Z = R as shown in figure (c). From figure (c), V_{L} = IX_{L} and V_{C} = IX_{C, }and these two are equal in magnitude but opposite in phase. Hence, they cancel each other. The applied voltage, V drops entirely across R. So that V = V_{R}. The circuit impedance Z = R. The phasor diagram for **series electrical resonance** is shown in figure (d). It means that impedance of the circuit equals the ohmic resistance R so that current is maximum in

**the AC series RLC circuit**.

## A.C. CIRCUITS TOPIC

- Introduction Of AC Circuits In Electrical Engineering
- How emf is induced in a single-phase system? single phase generation.
- Explain what is ac quantity: and the Advantages of AC over DC in circuits
- What is waveform, amplitude, cycle, time-period, phase & phase difference
- Define RMS & average value as applied to A.C. voltage & current
- What is the form factor? crest factor? peak factor? & power factor? in ac circuits
- what is phasor diagram, phasor algebra, leading & lagging ac quantities
- Phasor representation of alternating quantities – resistive, inductive, capacitive
- What is the R-L-C series connection for the A.C. circuit? Explanation
- What is the series combination of the R-L circuit? Explanation
- Define what is an active power, reactive power, apparent power & power factor
- Explain what is the series combination of R-C circuit in electrical engineering
- What are simple parallel AC circuits? Explanation -electrical engineering
- Resonance as applicable to simple RLC series circuit? effect on circuit performance
- Explain the three-phase generation of voltage? electrical engineering
- Explain in detail what is star and delta three-phase system?
- The relation between phase voltage & line voltage in case of balanced star connected load
- relationship between line current & phase current for delta connected 3 load
- The relation between power consumed in a balanced star & delta connection

*Thank for Visiting www.electricaltpoint.com for more electrical and other related posts be with us*.