All Q&A

Find the current in each branch of the network using Kirchhoff’s law


22 June, 2022
Applying KVL in mesh I, II and II respectively \(-2I_1-3I_2+{7I}_3=12\) … (1)


  • Star – delta conversion
  • Delta – star conversion with the help of a purely resistive circuit
22 June, 2022
In this transformation any resistance in delta network can be found out if the resistances of corresponding star network are known. Here the branch resistances in the star connections are

Derive an expression for the resonant frequency of a parallel circuit, one branch consisting of a coil of inductance L and resistance R and the other branch of capacitance C.

22 June, 2022
The series RL circuit with parallel C is given in Fig. 19. The designed circuit consists of resistance R, inductance L are in series with parallel configuration of capacitance C. Let us consider the current I flowing through the RLC circuit by the a.c. voltage source with constant value of V.

The galvanometer shown in the circuit has a resistance of 5 Ω. Find the current through the galvanometer using Thevenin’s theorem.


22 June, 2022
Equivalent resistance of the circuit \(R_{th}=\frac{10\times15}{10+15}+\frac{12\times16}{12+16}=6+6.86=12.86\ \mathrm{\Omega}\)

Derive the expression of quality factor of series R-L-C circuit at resonance.

22 June, 2022
The quality factor is , in general, defined as the ratio of resonant frequency to bandwidth. It is given by