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PHXII15:COMMUNICATION SYSTEMS

356773 A carrier wave of peak voltage $14 V$ is used for transmitting a message signal given to achieve a modulation index of $80 %$ will be:

1

22.4 V

2

7 V

3

11.2 V

4

28 V

Explanation:

$μ = \frac{A_{m}}{A_{c}}$
Given
$A_{c} = 14 V, μ = 0.8$
$\Rightarrow A_{m} = 11.2 V$

JEE - 2018

PHXII15:COMMUNICATION SYSTEMS

356774 A message signal of frequency $5 k H z$ is used to modulate a carrier signal of frequency $2 M H z$ . The bandwidth for amplitude modulation is

1

10 k H z

2

20 k H z

3

2.5 k H z

4

5 k H z

Explanation:

Frequency of message signal, $f_{m} = 5 k H z$
Frequency of carrier signal, $f_{c} = 2 M H z$
The bandwidth of amplitude modulation is
$2 f_{m} = 2 \times 5 = 10 k H z$

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356775 Choose the correct statement:

1 In amplitude modulation the frequency of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

2 In frequency modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

3 In frequency modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the frequency of the audio signal.

4 In amplitude modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

PHXII15:COMMUNICATION SYSTEMS

356776 The amplitude modulated current is given by $i = 125 [1 + 0.6 \sin 2900 t] \sin 10^{6} t$ . The depth of modulation is

1

60 %

2

6 %

3

36 %

4

66 %

Explanation:

$μ = 0.6 \times 100 = 60 %$

PHXII15:COMMUNICATION SYSTEMS

356773 A carrier wave of peak voltage $14 V$ is used for transmitting a message signal given to achieve a modulation index of $80 %$ will be:

1

22.4 V

2

7 V

3

11.2 V

4

28 V

Explanation:

$μ = \frac{A_{m}}{A_{c}}$
Given
$A_{c} = 14 V, μ = 0.8$
$\Rightarrow A_{m} = 11.2 V$

JEE - 2018

PHXII15:COMMUNICATION SYSTEMS

356774 A message signal of frequency $5 k H z$ is used to modulate a carrier signal of frequency $2 M H z$ . The bandwidth for amplitude modulation is

1

10 k H z

2

20 k H z

3

2.5 k H z

4

5 k H z

Explanation:

Frequency of message signal, $f_{m} = 5 k H z$
Frequency of carrier signal, $f_{c} = 2 M H z$
The bandwidth of amplitude modulation is
$2 f_{m} = 2 \times 5 = 10 k H z$

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356775 Choose the correct statement:

1 In amplitude modulation the frequency of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

2 In frequency modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

3 In frequency modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the frequency of the audio signal.

4 In amplitude modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

PHXII15:COMMUNICATION SYSTEMS

356776 The amplitude modulated current is given by $i = 125 [1 + 0.6 \sin 2900 t] \sin 10^{6} t$ . The depth of modulation is

1

60 %

2

6 %

3

36 %

4

66 %

Explanation:

$μ = 0.6 \times 100 = 60 %$

PHXII15:COMMUNICATION SYSTEMS

356773 A carrier wave of peak voltage $14 V$ is used for transmitting a message signal given to achieve a modulation index of $80 %$ will be:

1

22.4 V

2

7 V

3

11.2 V

4

28 V

Explanation:

$μ = \frac{A_{m}}{A_{c}}$
Given
$A_{c} = 14 V, μ = 0.8$
$\Rightarrow A_{m} = 11.2 V$

JEE - 2018

PHXII15:COMMUNICATION SYSTEMS

356774 A message signal of frequency $5 k H z$ is used to modulate a carrier signal of frequency $2 M H z$ . The bandwidth for amplitude modulation is

1

10 k H z

2

20 k H z

3

2.5 k H z

4

5 k H z

Explanation:

Frequency of message signal, $f_{m} = 5 k H z$
Frequency of carrier signal, $f_{c} = 2 M H z$
The bandwidth of amplitude modulation is
$2 f_{m} = 2 \times 5 = 10 k H z$

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356775 Choose the correct statement:

1 In amplitude modulation the frequency of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

2 In frequency modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

3 In frequency modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the frequency of the audio signal.

4 In amplitude modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

PHXII15:COMMUNICATION SYSTEMS

356776 The amplitude modulated current is given by $i = 125 [1 + 0.6 \sin 2900 t] \sin 10^{6} t$ . The depth of modulation is

1

60 %

2

6 %

3

36 %

4

66 %

Explanation:

$μ = 0.6 \times 100 = 60 %$

PHXII15:COMMUNICATION SYSTEMS

356773 A carrier wave of peak voltage $14 V$ is used for transmitting a message signal given to achieve a modulation index of $80 %$ will be:

1

22.4 V

2

7 V

3

11.2 V

4

28 V

Explanation:

$μ = \frac{A_{m}}{A_{c}}$
Given
$A_{c} = 14 V, μ = 0.8$
$\Rightarrow A_{m} = 11.2 V$

JEE - 2018

PHXII15:COMMUNICATION SYSTEMS

356774 A message signal of frequency $5 k H z$ is used to modulate a carrier signal of frequency $2 M H z$ . The bandwidth for amplitude modulation is

1

10 k H z

2

20 k H z

3

2.5 k H z

4

5 k H z

Explanation:

Frequency of message signal, $f_{m} = 5 k H z$
Frequency of carrier signal, $f_{c} = 2 M H z$
The bandwidth of amplitude modulation is
$2 f_{m} = 2 \times 5 = 10 k H z$

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356775 Choose the correct statement:

1 In amplitude modulation the frequency of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

2 In frequency modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

3 In frequency modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the frequency of the audio signal.

4 In amplitude modulation the amplitude of the high frequency carrier wave is made to vary in proportion to the amplitude of the audio signal.

PHXII15:COMMUNICATION SYSTEMS

356776 The amplitude modulated current is given by $i = 125 [1 + 0.6 \sin 2900 t] \sin 10^{6} t$ . The depth of modulation is

1

60 %

2

6 %

3

36 %

4

66 %

Explanation:

$μ = 0.6 \times 100 = 60 %$

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