QBManager

Alternating Current

155107 If wattless current flows in the $AC$ circuit, then the circuit is :

1 Purely Resistive circuit

2 Purely Inductive circuit

3 LCR series circuit

4 RC series circuit only

Explanation:

B If wattless current flows in the AC circuit then the circuit is purely inductive circuit.
$θ = π / 2$
$\cos π / 2 = 0$
Average power $= 0$

JEE Main-25.06.2022

Alternating Current

155108 To increase the resonant frequency in series LCR circuit,

1 Source frequency should be increased

2 Another resistance should be added in series with the first resistance

3 Another capacitor should be added in series with the first capacitor

4 The source frequency should be decreased

Explanation:

C Resonant frequency $= \frac{1}{\sqrt{LC}} = ω_{0}$
If we decrease $C, ω_{0}$ would increase
Another capacitor should be added in series

JEE Main-25.07.2022

Alternating Current

155109 In a $R C$ circuit. where $R$ is resistance and $C$ is capacitance which of the following has the dimension of time.

1

R / C

2

C / R

3

\sqrt{RC}

4

RC

Explanation:

D In RC circuit,
$RC = \frac{V}{I} \times \frac{q}{V} [∵ R = \frac{V}{I} and q = CV]$
$RC = \frac{q}{I} [I = \frac{q}{t}]$
$RC = t$
Hence, RC will have same dimensional formula of time.

TS EAMCET 18.07.2022

Alternating Current

155123 When a pure resistor is connected to an $AC$ source, the phase difference between the voltage and the current through the resistor is

1

90^{\circ}

2

180^{\circ}

3

45^{\circ}

4

0^{\circ}

Explanation:

D Let us consider a pure resistive circuit shown in figure given below -

Applying KVL in loop,
$V_{S} = V_{R} = I_{S} R$
From phasor diagram we can see that current and voltage both are in phase. Hence phase difference between them are $0^{\circ}$ .

AP EAMCET (18.09.2020) Shift-II

Alternating Current

155128 With the gradual increase in frequency of an a.c. supply, the impedance of an L-C-R series circuit

1 remains constant.

2 decreases.

3 first decreases, becomes minimum and then increases.

4 increases.

Explanation:

C In an LCR circuit the impendence and current depend upon the frequency (f). According to question if frequency is increases then $X_{L} = ω L$ will increases and $X_{C} = \frac{1}{ω C}$ is decreased.

So, impedance of the circuit first decreases then increases after reaching a minimum value.

MHT-CET 2020

Alternating Current

155107 If wattless current flows in the $AC$ circuit, then the circuit is :

1 Purely Resistive circuit

2 Purely Inductive circuit

3 LCR series circuit

4 RC series circuit only

Explanation:

B If wattless current flows in the AC circuit then the circuit is purely inductive circuit.
$θ = π / 2$
$\cos π / 2 = 0$
Average power $= 0$

JEE Main-25.06.2022

Alternating Current

155108 To increase the resonant frequency in series LCR circuit,

1 Source frequency should be increased

2 Another resistance should be added in series with the first resistance

3 Another capacitor should be added in series with the first capacitor

4 The source frequency should be decreased

Explanation:

C Resonant frequency $= \frac{1}{\sqrt{LC}} = ω_{0}$
If we decrease $C, ω_{0}$ would increase
Another capacitor should be added in series

JEE Main-25.07.2022

Alternating Current

155109 In a $R C$ circuit. where $R$ is resistance and $C$ is capacitance which of the following has the dimension of time.

1

R / C

2

C / R

3

\sqrt{RC}

4

RC

Explanation:

D In RC circuit,
$RC = \frac{V}{I} \times \frac{q}{V} [∵ R = \frac{V}{I} and q = CV]$
$RC = \frac{q}{I} [I = \frac{q}{t}]$
$RC = t$
Hence, RC will have same dimensional formula of time.

TS EAMCET 18.07.2022

Alternating Current

155123 When a pure resistor is connected to an $AC$ source, the phase difference between the voltage and the current through the resistor is

1

90^{\circ}

2

180^{\circ}

3

45^{\circ}

4

0^{\circ}

Explanation:

D Let us consider a pure resistive circuit shown in figure given below -

Applying KVL in loop,
$V_{S} = V_{R} = I_{S} R$
From phasor diagram we can see that current and voltage both are in phase. Hence phase difference between them are $0^{\circ}$ .

AP EAMCET (18.09.2020) Shift-II

Alternating Current

155128 With the gradual increase in frequency of an a.c. supply, the impedance of an L-C-R series circuit

1 remains constant.

2 decreases.

3 first decreases, becomes minimum and then increases.

4 increases.

Explanation:

C In an LCR circuit the impendence and current depend upon the frequency (f). According to question if frequency is increases then $X_{L} = ω L$ will increases and $X_{C} = \frac{1}{ω C}$ is decreased.

So, impedance of the circuit first decreases then increases after reaching a minimum value.

MHT-CET 2020

Alternating Current

155107 If wattless current flows in the $AC$ circuit, then the circuit is :

1 Purely Resistive circuit

2 Purely Inductive circuit

3 LCR series circuit

4 RC series circuit only

Explanation:

B If wattless current flows in the AC circuit then the circuit is purely inductive circuit.
$θ = π / 2$
$\cos π / 2 = 0$
Average power $= 0$

JEE Main-25.06.2022

Alternating Current

155108 To increase the resonant frequency in series LCR circuit,

1 Source frequency should be increased

2 Another resistance should be added in series with the first resistance

3 Another capacitor should be added in series with the first capacitor

4 The source frequency should be decreased

Explanation:

C Resonant frequency $= \frac{1}{\sqrt{LC}} = ω_{0}$
If we decrease $C, ω_{0}$ would increase
Another capacitor should be added in series

JEE Main-25.07.2022

Alternating Current

155109 In a $R C$ circuit. where $R$ is resistance and $C$ is capacitance which of the following has the dimension of time.

1

R / C

2

C / R

3

\sqrt{RC}

4

RC

Explanation:

D In RC circuit,
$RC = \frac{V}{I} \times \frac{q}{V} [∵ R = \frac{V}{I} and q = CV]$
$RC = \frac{q}{I} [I = \frac{q}{t}]$
$RC = t$
Hence, RC will have same dimensional formula of time.

TS EAMCET 18.07.2022

Alternating Current

155123 When a pure resistor is connected to an $AC$ source, the phase difference between the voltage and the current through the resistor is

1

90^{\circ}

2

180^{\circ}

3

45^{\circ}

4

0^{\circ}

Explanation:

D Let us consider a pure resistive circuit shown in figure given below -

Applying KVL in loop,
$V_{S} = V_{R} = I_{S} R$
From phasor diagram we can see that current and voltage both are in phase. Hence phase difference between them are $0^{\circ}$ .

AP EAMCET (18.09.2020) Shift-II

Alternating Current

155128 With the gradual increase in frequency of an a.c. supply, the impedance of an L-C-R series circuit

1 remains constant.

2 decreases.

3 first decreases, becomes minimum and then increases.

4 increases.

Explanation:

C In an LCR circuit the impendence and current depend upon the frequency (f). According to question if frequency is increases then $X_{L} = ω L$ will increases and $X_{C} = \frac{1}{ω C}$ is decreased.

So, impedance of the circuit first decreases then increases after reaching a minimum value.

MHT-CET 2020

Alternating Current

155107 If wattless current flows in the $AC$ circuit, then the circuit is :

1 Purely Resistive circuit

2 Purely Inductive circuit

3 LCR series circuit

4 RC series circuit only

Explanation:

B If wattless current flows in the AC circuit then the circuit is purely inductive circuit.
$θ = π / 2$
$\cos π / 2 = 0$
Average power $= 0$

JEE Main-25.06.2022

Alternating Current

155108 To increase the resonant frequency in series LCR circuit,

1 Source frequency should be increased

2 Another resistance should be added in series with the first resistance

3 Another capacitor should be added in series with the first capacitor

4 The source frequency should be decreased

Explanation:

C Resonant frequency $= \frac{1}{\sqrt{LC}} = ω_{0}$
If we decrease $C, ω_{0}$ would increase
Another capacitor should be added in series

JEE Main-25.07.2022

Alternating Current

155109 In a $R C$ circuit. where $R$ is resistance and $C$ is capacitance which of the following has the dimension of time.

1

R / C

2

C / R

3

\sqrt{RC}

4

RC

Explanation:

D In RC circuit,
$RC = \frac{V}{I} \times \frac{q}{V} [∵ R = \frac{V}{I} and q = CV]$
$RC = \frac{q}{I} [I = \frac{q}{t}]$
$RC = t$
Hence, RC will have same dimensional formula of time.

TS EAMCET 18.07.2022

Alternating Current

155123 When a pure resistor is connected to an $AC$ source, the phase difference between the voltage and the current through the resistor is

1

90^{\circ}

2

180^{\circ}

3

45^{\circ}

4

0^{\circ}

Explanation:

D Let us consider a pure resistive circuit shown in figure given below -

Applying KVL in loop,
$V_{S} = V_{R} = I_{S} R$
From phasor diagram we can see that current and voltage both are in phase. Hence phase difference between them are $0^{\circ}$ .

AP EAMCET (18.09.2020) Shift-II

Alternating Current

155128 With the gradual increase in frequency of an a.c. supply, the impedance of an L-C-R series circuit

1 remains constant.

2 decreases.

3 first decreases, becomes minimum and then increases.

4 increases.

Explanation:

C In an LCR circuit the impendence and current depend upon the frequency (f). According to question if frequency is increases then $X_{L} = ω L$ will increases and $X_{C} = \frac{1}{ω C}$ is decreased.

So, impedance of the circuit first decreases then increases after reaching a minimum value.

MHT-CET 2020

Alternating Current

155107 If wattless current flows in the $AC$ circuit, then the circuit is :

1 Purely Resistive circuit

2 Purely Inductive circuit

3 LCR series circuit

4 RC series circuit only

Explanation:

B If wattless current flows in the AC circuit then the circuit is purely inductive circuit.
$θ = π / 2$
$\cos π / 2 = 0$
Average power $= 0$

JEE Main-25.06.2022

Alternating Current

155108 To increase the resonant frequency in series LCR circuit,

1 Source frequency should be increased

2 Another resistance should be added in series with the first resistance

3 Another capacitor should be added in series with the first capacitor

4 The source frequency should be decreased

Explanation:

C Resonant frequency $= \frac{1}{\sqrt{LC}} = ω_{0}$
If we decrease $C, ω_{0}$ would increase
Another capacitor should be added in series

JEE Main-25.07.2022

Alternating Current

155109 In a $R C$ circuit. where $R$ is resistance and $C$ is capacitance which of the following has the dimension of time.

1

R / C

2

C / R

3

\sqrt{RC}

4

RC

Explanation:

D In RC circuit,
$RC = \frac{V}{I} \times \frac{q}{V} [∵ R = \frac{V}{I} and q = CV]$
$RC = \frac{q}{I} [I = \frac{q}{t}]$
$RC = t$
Hence, RC will have same dimensional formula of time.

TS EAMCET 18.07.2022

Alternating Current

155123 When a pure resistor is connected to an $AC$ source, the phase difference between the voltage and the current through the resistor is

1

90^{\circ}

2

180^{\circ}

3

45^{\circ}

4

0^{\circ}

Explanation:

D Let us consider a pure resistive circuit shown in figure given below -

Applying KVL in loop,
$V_{S} = V_{R} = I_{S} R$
From phasor diagram we can see that current and voltage both are in phase. Hence phase difference between them are $0^{\circ}$ .

AP EAMCET (18.09.2020) Shift-II

Alternating Current

155128 With the gradual increase in frequency of an a.c. supply, the impedance of an L-C-R series circuit

1 remains constant.

2 decreases.

3 first decreases, becomes minimum and then increases.

4 increases.

Explanation:

C In an LCR circuit the impendence and current depend upon the frequency (f). According to question if frequency is increases then $X_{L} = ω L$ will increases and $X_{C} = \frac{1}{ω C}$ is decreased.

So, impedance of the circuit first decreases then increases after reaching a minimum value.

MHT-CET 2020