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PHXII15:COMMUNICATION SYSTEMS

356815 Read the Statement - A and Statement - B carefully to mark the correct options given below:
Statement A :
For transmitting a signal, size of antenns (1) should be comparable to wavelength of signal (at least $l = \frac{λ}{4}$ in dimension)
Statement B :
In amplitude modulation, amplitude of carrier wave remains constant (unchanged).

1 Statement A is correct but Statement B is incorrect.

2 Both Statement A and Statement B are incorrect.

3 Both Statement A and Statement B are correct.

4 Statement A is incorrect but Statement B is correct.

Explanation:

For transmitting a signal, antenna should have a size comparable to the wavelength of the signal $i . e .,$ at least $1 / 4$ in dimension, so that the antenna properly senses the time variation of the signal. The amplitude of the carrier wave is varied in accordance with the message signal is termed as amplitude modulation. So, statement A is correct but statement B is incorrect.

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356816 A $1 k W$ signal is transmitted using a communication channel which provides attenuation at the rate of $- 2 d B$ per $k m$ . If the communication channel has a total length of $10 k m$ , what will the power of the signal received?

1

5 W

2

7 W

3

8 W

4

10 W

Explanation:

Loss suffered in the communication channel
$= (- 2) 10 = - 20 d B$
$∴ 10 \log (\frac{P_{0}}{P_{i}}) = - 20 \Rightarrow \log (\frac{P_{0}}{P_{i}}) = - 2$
$∴ (\frac{P_{0}}{P_{i}}) = 10^{- 2} = \frac{1}{100}$
$∴ P_{0} = \frac{P_{i}}{100} = \frac{1000}{100} = 10 W$

PHXII15:COMMUNICATION SYSTEMS

356817 In satellite communication, the uplink frequency band used is

1

5.925 - 6.425 G H z

2

420 - 890 M H z

3

3.7 - 4.2 G H z

4

76 - 88 M H z

Explanation:

In satellite communication, the up link frequency range used is 5.925 to $6.425 G H z$ .

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356818 As the e.m. waves travel in free space

1 Absorption takes place

2 Attenuation takes place

3 Redfraction takes place

4 Reflection takes place

PHXII15:COMMUNICATION SYSTEMS

356819 A transmitting antenna is kept on the surface of the earth. The minimum height of receiving antenna required to receive the signal in line of sight at $4 k m$ distance from it is $x \times 10^{- 2} m$ . The value of $x$ is (Let radius of earth $R = 6400 k m$ )

1 125

2 12.5

3 1.25

4 1250

Explanation:

Here, $d_{r} = \sqrt{2 h_{r} R} ∴ h_{r} = \frac{d_{r}^{2}}{2 R}$ $= \frac{(4 k m)^{2}}{2 (6400 k m)} = (\frac{1}{800}) k m = 1.25 m$ $= 125 \times 10^{- 2} m$ Hence, $x = 125$

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356815 Read the Statement - A and Statement - B carefully to mark the correct options given below:
Statement A :
For transmitting a signal, size of antenns (1) should be comparable to wavelength of signal (at least $l = \frac{λ}{4}$ in dimension)
Statement B :
In amplitude modulation, amplitude of carrier wave remains constant (unchanged).

1 Statement A is correct but Statement B is incorrect.

2 Both Statement A and Statement B are incorrect.

3 Both Statement A and Statement B are correct.

4 Statement A is incorrect but Statement B is correct.

Explanation:

For transmitting a signal, antenna should have a size comparable to the wavelength of the signal $i . e .,$ at least $1 / 4$ in dimension, so that the antenna properly senses the time variation of the signal. The amplitude of the carrier wave is varied in accordance with the message signal is termed as amplitude modulation. So, statement A is correct but statement B is incorrect.

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356816 A $1 k W$ signal is transmitted using a communication channel which provides attenuation at the rate of $- 2 d B$ per $k m$ . If the communication channel has a total length of $10 k m$ , what will the power of the signal received?

1

5 W

2

7 W

3

8 W

4

10 W

Explanation:

Loss suffered in the communication channel
$= (- 2) 10 = - 20 d B$
$∴ 10 \log (\frac{P_{0}}{P_{i}}) = - 20 \Rightarrow \log (\frac{P_{0}}{P_{i}}) = - 2$
$∴ (\frac{P_{0}}{P_{i}}) = 10^{- 2} = \frac{1}{100}$
$∴ P_{0} = \frac{P_{i}}{100} = \frac{1000}{100} = 10 W$

PHXII15:COMMUNICATION SYSTEMS

356817 In satellite communication, the uplink frequency band used is

1

5.925 - 6.425 G H z

2

420 - 890 M H z

3

3.7 - 4.2 G H z

4

76 - 88 M H z

Explanation:

In satellite communication, the up link frequency range used is 5.925 to $6.425 G H z$ .

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356818 As the e.m. waves travel in free space

1 Absorption takes place

2 Attenuation takes place

3 Redfraction takes place

4 Reflection takes place

PHXII15:COMMUNICATION SYSTEMS

356819 A transmitting antenna is kept on the surface of the earth. The minimum height of receiving antenna required to receive the signal in line of sight at $4 k m$ distance from it is $x \times 10^{- 2} m$ . The value of $x$ is (Let radius of earth $R = 6400 k m$ )

1 125

2 12.5

3 1.25

4 1250

Explanation:

Here, $d_{r} = \sqrt{2 h_{r} R} ∴ h_{r} = \frac{d_{r}^{2}}{2 R}$ $= \frac{(4 k m)^{2}}{2 (6400 k m)} = (\frac{1}{800}) k m = 1.25 m$ $= 125 \times 10^{- 2} m$ Hence, $x = 125$

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356815 Read the Statement - A and Statement - B carefully to mark the correct options given below:
Statement A :
For transmitting a signal, size of antenns (1) should be comparable to wavelength of signal (at least $l = \frac{λ}{4}$ in dimension)
Statement B :
In amplitude modulation, amplitude of carrier wave remains constant (unchanged).

1 Statement A is correct but Statement B is incorrect.

2 Both Statement A and Statement B are incorrect.

3 Both Statement A and Statement B are correct.

4 Statement A is incorrect but Statement B is correct.

Explanation:

For transmitting a signal, antenna should have a size comparable to the wavelength of the signal $i . e .,$ at least $1 / 4$ in dimension, so that the antenna properly senses the time variation of the signal. The amplitude of the carrier wave is varied in accordance with the message signal is termed as amplitude modulation. So, statement A is correct but statement B is incorrect.

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356816 A $1 k W$ signal is transmitted using a communication channel which provides attenuation at the rate of $- 2 d B$ per $k m$ . If the communication channel has a total length of $10 k m$ , what will the power of the signal received?

1

5 W

2

7 W

3

8 W

4

10 W

Explanation:

Loss suffered in the communication channel
$= (- 2) 10 = - 20 d B$
$∴ 10 \log (\frac{P_{0}}{P_{i}}) = - 20 \Rightarrow \log (\frac{P_{0}}{P_{i}}) = - 2$
$∴ (\frac{P_{0}}{P_{i}}) = 10^{- 2} = \frac{1}{100}$
$∴ P_{0} = \frac{P_{i}}{100} = \frac{1000}{100} = 10 W$

PHXII15:COMMUNICATION SYSTEMS

356817 In satellite communication, the uplink frequency band used is

1

5.925 - 6.425 G H z

2

420 - 890 M H z

3

3.7 - 4.2 G H z

4

76 - 88 M H z

Explanation:

In satellite communication, the up link frequency range used is 5.925 to $6.425 G H z$ .

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356818 As the e.m. waves travel in free space

1 Absorption takes place

2 Attenuation takes place

3 Redfraction takes place

4 Reflection takes place

PHXII15:COMMUNICATION SYSTEMS

356819 A transmitting antenna is kept on the surface of the earth. The minimum height of receiving antenna required to receive the signal in line of sight at $4 k m$ distance from it is $x \times 10^{- 2} m$ . The value of $x$ is (Let radius of earth $R = 6400 k m$ )

1 125

2 12.5

3 1.25

4 1250

Explanation:

Here, $d_{r} = \sqrt{2 h_{r} R} ∴ h_{r} = \frac{d_{r}^{2}}{2 R}$ $= \frac{(4 k m)^{2}}{2 (6400 k m)} = (\frac{1}{800}) k m = 1.25 m$ $= 125 \times 10^{- 2} m$ Hence, $x = 125$

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356815 Read the Statement - A and Statement - B carefully to mark the correct options given below:
Statement A :
For transmitting a signal, size of antenns (1) should be comparable to wavelength of signal (at least $l = \frac{λ}{4}$ in dimension)
Statement B :
In amplitude modulation, amplitude of carrier wave remains constant (unchanged).

1 Statement A is correct but Statement B is incorrect.

2 Both Statement A and Statement B are incorrect.

3 Both Statement A and Statement B are correct.

4 Statement A is incorrect but Statement B is correct.

Explanation:

For transmitting a signal, antenna should have a size comparable to the wavelength of the signal $i . e .,$ at least $1 / 4$ in dimension, so that the antenna properly senses the time variation of the signal. The amplitude of the carrier wave is varied in accordance with the message signal is termed as amplitude modulation. So, statement A is correct but statement B is incorrect.

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356816 A $1 k W$ signal is transmitted using a communication channel which provides attenuation at the rate of $- 2 d B$ per $k m$ . If the communication channel has a total length of $10 k m$ , what will the power of the signal received?

1

5 W

2

7 W

3

8 W

4

10 W

Explanation:

Loss suffered in the communication channel
$= (- 2) 10 = - 20 d B$
$∴ 10 \log (\frac{P_{0}}{P_{i}}) = - 20 \Rightarrow \log (\frac{P_{0}}{P_{i}}) = - 2$
$∴ (\frac{P_{0}}{P_{i}}) = 10^{- 2} = \frac{1}{100}$
$∴ P_{0} = \frac{P_{i}}{100} = \frac{1000}{100} = 10 W$

PHXII15:COMMUNICATION SYSTEMS

356817 In satellite communication, the uplink frequency band used is

1

5.925 - 6.425 G H z

2

420 - 890 M H z

3

3.7 - 4.2 G H z

4

76 - 88 M H z

Explanation:

In satellite communication, the up link frequency range used is 5.925 to $6.425 G H z$ .

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356818 As the e.m. waves travel in free space

1 Absorption takes place

2 Attenuation takes place

3 Redfraction takes place

4 Reflection takes place

PHXII15:COMMUNICATION SYSTEMS

356819 A transmitting antenna is kept on the surface of the earth. The minimum height of receiving antenna required to receive the signal in line of sight at $4 k m$ distance from it is $x \times 10^{- 2} m$ . The value of $x$ is (Let radius of earth $R = 6400 k m$ )

1 125

2 12.5

3 1.25

4 1250

Explanation:

Here, $d_{r} = \sqrt{2 h_{r} R} ∴ h_{r} = \frac{d_{r}^{2}}{2 R}$ $= \frac{(4 k m)^{2}}{2 (6400 k m)} = (\frac{1}{800}) k m = 1.25 m$ $= 125 \times 10^{- 2} m$ Hence, $x = 125$

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356815 Read the Statement - A and Statement - B carefully to mark the correct options given below:
Statement A :
For transmitting a signal, size of antenns (1) should be comparable to wavelength of signal (at least $l = \frac{λ}{4}$ in dimension)
Statement B :
In amplitude modulation, amplitude of carrier wave remains constant (unchanged).

1 Statement A is correct but Statement B is incorrect.

2 Both Statement A and Statement B are incorrect.

3 Both Statement A and Statement B are correct.

4 Statement A is incorrect but Statement B is correct.

Explanation:

For transmitting a signal, antenna should have a size comparable to the wavelength of the signal $i . e .,$ at least $1 / 4$ in dimension, so that the antenna properly senses the time variation of the signal. The amplitude of the carrier wave is varied in accordance with the message signal is termed as amplitude modulation. So, statement A is correct but statement B is incorrect.

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356816 A $1 k W$ signal is transmitted using a communication channel which provides attenuation at the rate of $- 2 d B$ per $k m$ . If the communication channel has a total length of $10 k m$ , what will the power of the signal received?

1

5 W

2

7 W

3

8 W

4

10 W

Explanation:

Loss suffered in the communication channel
$= (- 2) 10 = - 20 d B$
$∴ 10 \log (\frac{P_{0}}{P_{i}}) = - 20 \Rightarrow \log (\frac{P_{0}}{P_{i}}) = - 2$
$∴ (\frac{P_{0}}{P_{i}}) = 10^{- 2} = \frac{1}{100}$
$∴ P_{0} = \frac{P_{i}}{100} = \frac{1000}{100} = 10 W$

PHXII15:COMMUNICATION SYSTEMS

356817 In satellite communication, the uplink frequency band used is

1

5.925 - 6.425 G H z

2

420 - 890 M H z

3

3.7 - 4.2 G H z

4

76 - 88 M H z

Explanation:

In satellite communication, the up link frequency range used is 5.925 to $6.425 G H z$ .

JEE - 2023

PHXII15:COMMUNICATION SYSTEMS

356818 As the e.m. waves travel in free space

1 Absorption takes place

2 Attenuation takes place

3 Redfraction takes place

4 Reflection takes place

PHXII15:COMMUNICATION SYSTEMS

356819 A transmitting antenna is kept on the surface of the earth. The minimum height of receiving antenna required to receive the signal in line of sight at $4 k m$ distance from it is $x \times 10^{- 2} m$ . The value of $x$ is (Let radius of earth $R = 6400 k m$ )

1 125

2 12.5

3 1.25

4 1250

Explanation:

Here, $d_{r} = \sqrt{2 h_{r} R} ∴ h_{r} = \frac{d_{r}^{2}}{2 R}$ $= \frac{(4 k m)^{2}}{2 (6400 k m)} = (\frac{1}{800}) k m = 1.25 m$ $= 125 \times 10^{- 2} m$ Hence, $x = 125$

JEE - 2023