QBManager

AC (NCERT)

274669 In which of the following circuits the maximum power dissipation is observed?

1 Pure capacitive circuit

2 Pure resistive circuit

3 Pure inductive circuit

4 None of these

NCERT Page-252 / N-191

AC (NCERT)

274670 The power factor in a circuit connected to an A.C. The value of power factor is

1 unity when the circuit contains an ideal inductance only

2 unity when the circuit contains an ideal resistance only

3 zero when the circuit contains an ideal resistance only

4 unity when the circuit contains an ideal capacitance only

Explanation:

(b) $cos ϕ = \frac{R}{Z}$ , where $Z$ is the impedance &
$Z = \sqrt{R^{2} + {(X_{L} - X_{C})}^{2}}$ , if there is only resistance then $Z = R \Rightarrow cos ϕ = 1$ .

NCERT Page-252 / N-191

AC (NCERT)

274671 A sinusoidal voltage of peak value $283 V$ and frequency $50 Hz$ is applied to a series LCR circuit in which $R = 3 Ω$ , $L = 25.48 mH$ , and $C = 796 μ F$ , then the power dissipated at the resonant condition will be-

1

39.70 kW

2

26.70 kW

3

13.35 kW

4 Zero

Explanation:

(c) $V_{0} = 283 V, f = 50 Hz, R = 3 Ω, L = 25.48 mH$
$C = 796 μ F, {P |}_{at resonance} =$ ?
Power dissipated $P = I^{2} R$
$I = \frac{I_{0}}{\sqrt{2}} = \frac{1}{\sqrt{2}} (\frac{283}{3}) = 66.7 A$
$P = I^{2} R = {(66.7)}^{2} 3 = 13.35 kW$

NCERT Page-252/ N-191

AC (NCERT)

274672 The power factor of an $A C$ circuit having resistance (R) and inductance (L) connected in series and an
angular velocity $ω$ is

1

R / ω L

2

R / (R^{2} ω^{2} L^{2})

3

ω L / R

4

R / {(R^{2} ω^{2} L^{2})}^{1 / 2}

NCERT Page-252/ N-191

AC (NCERT)

274669 In which of the following circuits the maximum power dissipation is observed?

1 Pure capacitive circuit

2 Pure resistive circuit

3 Pure inductive circuit

4 None of these

NCERT Page-252 / N-191

AC (NCERT)

274670 The power factor in a circuit connected to an A.C. The value of power factor is

1 unity when the circuit contains an ideal inductance only

2 unity when the circuit contains an ideal resistance only

3 zero when the circuit contains an ideal resistance only

4 unity when the circuit contains an ideal capacitance only

Explanation:

(b) $cos ϕ = \frac{R}{Z}$ , where $Z$ is the impedance &
$Z = \sqrt{R^{2} + {(X_{L} - X_{C})}^{2}}$ , if there is only resistance then $Z = R \Rightarrow cos ϕ = 1$ .

NCERT Page-252 / N-191

AC (NCERT)

274671 A sinusoidal voltage of peak value $283 V$ and frequency $50 Hz$ is applied to a series LCR circuit in which $R = 3 Ω$ , $L = 25.48 mH$ , and $C = 796 μ F$ , then the power dissipated at the resonant condition will be-

1

39.70 kW

2

26.70 kW

3

13.35 kW

4 Zero

Explanation:

(c) $V_{0} = 283 V, f = 50 Hz, R = 3 Ω, L = 25.48 mH$
$C = 796 μ F, {P |}_{at resonance} =$ ?
Power dissipated $P = I^{2} R$
$I = \frac{I_{0}}{\sqrt{2}} = \frac{1}{\sqrt{2}} (\frac{283}{3}) = 66.7 A$
$P = I^{2} R = {(66.7)}^{2} 3 = 13.35 kW$

NCERT Page-252/ N-191

AC (NCERT)

274672 The power factor of an $A C$ circuit having resistance (R) and inductance (L) connected in series and an
angular velocity $ω$ is

1

R / ω L

2

R / (R^{2} ω^{2} L^{2})

3

ω L / R

4

R / {(R^{2} ω^{2} L^{2})}^{1 / 2}

NCERT Page-252/ N-191

AC (NCERT)

274669 In which of the following circuits the maximum power dissipation is observed?

1 Pure capacitive circuit

2 Pure resistive circuit

3 Pure inductive circuit

4 None of these

NCERT Page-252 / N-191

AC (NCERT)

274670 The power factor in a circuit connected to an A.C. The value of power factor is

1 unity when the circuit contains an ideal inductance only

2 unity when the circuit contains an ideal resistance only

3 zero when the circuit contains an ideal resistance only

4 unity when the circuit contains an ideal capacitance only

Explanation:

(b) $cos ϕ = \frac{R}{Z}$ , where $Z$ is the impedance &
$Z = \sqrt{R^{2} + {(X_{L} - X_{C})}^{2}}$ , if there is only resistance then $Z = R \Rightarrow cos ϕ = 1$ .

NCERT Page-252 / N-191

AC (NCERT)

274671 A sinusoidal voltage of peak value $283 V$ and frequency $50 Hz$ is applied to a series LCR circuit in which $R = 3 Ω$ , $L = 25.48 mH$ , and $C = 796 μ F$ , then the power dissipated at the resonant condition will be-

1

39.70 kW

2

26.70 kW

3

13.35 kW

4 Zero

Explanation:

(c) $V_{0} = 283 V, f = 50 Hz, R = 3 Ω, L = 25.48 mH$
$C = 796 μ F, {P |}_{at resonance} =$ ?
Power dissipated $P = I^{2} R$
$I = \frac{I_{0}}{\sqrt{2}} = \frac{1}{\sqrt{2}} (\frac{283}{3}) = 66.7 A$
$P = I^{2} R = {(66.7)}^{2} 3 = 13.35 kW$

NCERT Page-252/ N-191

AC (NCERT)

274672 The power factor of an $A C$ circuit having resistance (R) and inductance (L) connected in series and an
angular velocity $ω$ is

1

R / ω L

2

R / (R^{2} ω^{2} L^{2})

3

ω L / R

4

R / {(R^{2} ω^{2} L^{2})}^{1 / 2}

NCERT Page-252/ N-191

AC (NCERT)

274669 In which of the following circuits the maximum power dissipation is observed?

1 Pure capacitive circuit

2 Pure resistive circuit

3 Pure inductive circuit

4 None of these

NCERT Page-252 / N-191

AC (NCERT)

274670 The power factor in a circuit connected to an A.C. The value of power factor is

1 unity when the circuit contains an ideal inductance only

2 unity when the circuit contains an ideal resistance only

3 zero when the circuit contains an ideal resistance only

4 unity when the circuit contains an ideal capacitance only

Explanation:

(b) $cos ϕ = \frac{R}{Z}$ , where $Z$ is the impedance &
$Z = \sqrt{R^{2} + {(X_{L} - X_{C})}^{2}}$ , if there is only resistance then $Z = R \Rightarrow cos ϕ = 1$ .

NCERT Page-252 / N-191

AC (NCERT)

274671 A sinusoidal voltage of peak value $283 V$ and frequency $50 Hz$ is applied to a series LCR circuit in which $R = 3 Ω$ , $L = 25.48 mH$ , and $C = 796 μ F$ , then the power dissipated at the resonant condition will be-

1

39.70 kW

2

26.70 kW

3

13.35 kW

4 Zero

Explanation:

(c) $V_{0} = 283 V, f = 50 Hz, R = 3 Ω, L = 25.48 mH$
$C = 796 μ F, {P |}_{at resonance} =$ ?
Power dissipated $P = I^{2} R$
$I = \frac{I_{0}}{\sqrt{2}} = \frac{1}{\sqrt{2}} (\frac{283}{3}) = 66.7 A$
$P = I^{2} R = {(66.7)}^{2} 3 = 13.35 kW$

NCERT Page-252/ N-191

AC (NCERT)

274672 The power factor of an $A C$ circuit having resistance (R) and inductance (L) connected in series and an
angular velocity $ω$ is

1

R / ω L

2

R / (R^{2} ω^{2} L^{2})

3

ω L / R

4

R / {(R^{2} ω^{2} L^{2})}^{1 / 2}

NCERT Page-252/ N-191