Resonance in Series LCR Circuit
PHXII07:ALTERNATING CURRENT

356266 Read the Statement - A and Statement - B carefully to mark the correct options given below:
Statement A :
When the frequency of an a.c. source in a series \(L C R\) circuit increases, the current in the circuit first increases, attains a maximum value and then decreases.
Statement B :
In a series \(L C R\) circuit, the value of power factor at resonance is one.

1 Statement A is incorrect but Statement B is correct.
2 Both Statement A and Statement B are correct.
3 Statement A is correct but Statement B is incorrect.
4 Both Statement A and Statement B are incorrect.
PHXII07:ALTERNATING CURRENT

356267 A series \(LCR\) circuit containing 5.0\(H\) inductor, \(80\mu F\) capacitor and \(40\Omega \) resistor is connected to 230\(V\) variable frequency ac source . The angular frequencies of the source at which power transferred to the circuit is half the power at the resonant angular frequency are likely to be :

1 50 \(rad/s\) and 25 \(rad/s\)
2 46\(rad/s\) and 54 \(rad/s\)
3 42\(rad/s\) and 58 \(rad/s\)
4 25 \(rad/s\) and 75 \(rad/s\)
PHXII07:ALTERNATING CURRENT

356268 In an \(LCR\) series resonant circuit which one of the following cannot be the expression for the \(Q \)- factor?

1 \(\frac{R}{{LC}}\)
2 \(\sqrt {\frac{L}{C}} \frac{1}{R}\)
3 \(\frac{1}{{\omega CR}}\)
4 \(\frac{{\omega L}}{R}\)
PHXII07:ALTERNATING CURRENT

356266 Read the Statement - A and Statement - B carefully to mark the correct options given below:
Statement A :
When the frequency of an a.c. source in a series \(L C R\) circuit increases, the current in the circuit first increases, attains a maximum value and then decreases.
Statement B :
In a series \(L C R\) circuit, the value of power factor at resonance is one.

1 Statement A is incorrect but Statement B is correct.
2 Both Statement A and Statement B are correct.
3 Statement A is correct but Statement B is incorrect.
4 Both Statement A and Statement B are incorrect.
PHXII07:ALTERNATING CURRENT

356267 A series \(LCR\) circuit containing 5.0\(H\) inductor, \(80\mu F\) capacitor and \(40\Omega \) resistor is connected to 230\(V\) variable frequency ac source . The angular frequencies of the source at which power transferred to the circuit is half the power at the resonant angular frequency are likely to be :

1 50 \(rad/s\) and 25 \(rad/s\)
2 46\(rad/s\) and 54 \(rad/s\)
3 42\(rad/s\) and 58 \(rad/s\)
4 25 \(rad/s\) and 75 \(rad/s\)
PHXII07:ALTERNATING CURRENT

356268 In an \(LCR\) series resonant circuit which one of the following cannot be the expression for the \(Q \)- factor?

1 \(\frac{R}{{LC}}\)
2 \(\sqrt {\frac{L}{C}} \frac{1}{R}\)
3 \(\frac{1}{{\omega CR}}\)
4 \(\frac{{\omega L}}{R}\)
PHXII07:ALTERNATING CURRENT

356266 Read the Statement - A and Statement - B carefully to mark the correct options given below:
Statement A :
When the frequency of an a.c. source in a series \(L C R\) circuit increases, the current in the circuit first increases, attains a maximum value and then decreases.
Statement B :
In a series \(L C R\) circuit, the value of power factor at resonance is one.

1 Statement A is incorrect but Statement B is correct.
2 Both Statement A and Statement B are correct.
3 Statement A is correct but Statement B is incorrect.
4 Both Statement A and Statement B are incorrect.
PHXII07:ALTERNATING CURRENT

356267 A series \(LCR\) circuit containing 5.0\(H\) inductor, \(80\mu F\) capacitor and \(40\Omega \) resistor is connected to 230\(V\) variable frequency ac source . The angular frequencies of the source at which power transferred to the circuit is half the power at the resonant angular frequency are likely to be :

1 50 \(rad/s\) and 25 \(rad/s\)
2 46\(rad/s\) and 54 \(rad/s\)
3 42\(rad/s\) and 58 \(rad/s\)
4 25 \(rad/s\) and 75 \(rad/s\)
PHXII07:ALTERNATING CURRENT

356268 In an \(LCR\) series resonant circuit which one of the following cannot be the expression for the \(Q \)- factor?

1 \(\frac{R}{{LC}}\)
2 \(\sqrt {\frac{L}{C}} \frac{1}{R}\)
3 \(\frac{1}{{\omega CR}}\)
4 \(\frac{{\omega L}}{R}\)