Home
Class 12
PHYSICS
A wave of frequency of 10 kHz and amplit...

A wave of frequency of 10 kHz and amplitude 20 volts is being used to modulate amplitude of carrier wave of frequency 1000 kHz and peak voltage 40 volts. Choose correct option regarding carrier modulated wave.

A

Equation of carrier modulated wave is `40{1+0.25sin20pi xx10^(3)t}sin(2pi xx10^(6)t)` and modulation index is 0.2

B

Equation of carrier modulated wave is `40(1+0.5sin20pixx10^(5)t}sin(2pixx10^(4)t)` and modulation index is 0.5

C

Equation of carried modulated wave is `40{1+0.5sin20pixx10^(3)t}sin(2pi xx10^(6)t)` and modulation index is 2

D

Equation of carrier modulated wave is `40{1+0.5sin20pixx10^(3)t)sin(2pixx10^(6)t)` and depth of modulation is 0.5

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem regarding the modulation of a carrier wave, we will follow these steps: ### Step 1: Identify the given parameters - Frequency of the message signal (fm) = 10 kHz = \(10 \times 10^3\) Hz - Amplitude of the message signal (Am) = 20 volts - Frequency of the carrier signal (fc) = 1000 kHz = \(1000 \times 10^3\) Hz = \(10^6\) Hz - Amplitude of the carrier signal (Ac) = 40 volts ### Step 2: Calculate the Modulating Index (μ) The modulating index (μ) is defined as the ratio of the amplitude of the message signal to the amplitude of the carrier signal: \[ \mu = \frac{A_m}{A_c} = \frac{20 \text{ V}}{40 \text{ V}} = \frac{1}{2} = 0.5 \] ### Step 3: Write the equations for the message and carrier signals The equation for the message signal can be expressed as: \[ m(t) = A_m \sin(2\pi f_m t) = 20 \sin(2\pi (10 \times 10^3) t) \] The equation for the carrier signal is: \[ c(t) = A_c \sin(2\pi f_c t) = 40 \sin(2\pi (10^6) t) \] ### Step 4: Write the equation for the modulated signal The equation for the amplitude-modulated wave (cmt) is given by: \[ c_m(t) = A_c \left(1 + \mu \sin(2\pi f_m t)\right) \sin(2\pi f_c t) \] Substituting the values we have: \[ c_m(t) = 40 \left(1 + 0.5 \sin(2\pi (10 \times 10^3) t)\right) \sin(2\pi (10^6) t) \] ### Step 5: Simplify the modulated signal equation This can be expanded to: \[ c_m(t) = 40 \sin(2\pi (10^6) t) + 20 \sin(2\pi (10 \times 10^3) t) \sin(2\pi (10^6) t) \] ### Step 6: Identify the characteristics of the modulated wave The modulated wave will have: - A carrier frequency of \(1000 kHz\) (or \(10^6 Hz\)) - A modulation frequency of \(10 kHz\) (or \(10^4 Hz\)) - A peak amplitude that varies between \(20 V\) and \(60 V\) (from the modulation). ### Conclusion The correct option regarding the carrier modulated wave is that it has a modulating index of \(0.5\) and the frequency components of the modulated signal will include both the carrier frequency and the modulation frequency.

To solve the problem regarding the modulation of a carrier wave, we will follow these steps: ### Step 1: Identify the given parameters - Frequency of the message signal (fm) = 10 kHz = \(10 \times 10^3\) Hz - Amplitude of the message signal (Am) = 20 volts - Frequency of the carrier signal (fc) = 1000 kHz = \(1000 \times 10^3\) Hz = \(10^6\) Hz - Amplitude of the carrier signal (Ac) = 40 volts ...
Promotional Banner

Similar Questions

Explore conceptually related problems

A signal of frequency 20 kHz and peak voltage of 5 volt is used to modulate a carrier wave of frequency 1.2 MHz and peak voltage 25 volts. Choose the correct statement.

A message signal of frequency 20 kHz and peak voltage of 20 volt is used to modulate a carrier wave of frequency 1 MHz and peak voltage of 20 volt. The modulation index will be :

A message signal of frequency 10 kHz and peak voltage 10 volt is used to modulate a carrier of frequency 1 MHz and peak voltage 20 volt. Find the modulation index.

A message signal of frequency 12 kHz and peak voltage 12 volt is used to modulate a carrier of frequency 1 MHz and peak voltage 24 volt. What is the modulation index and the side bands produced ?

A message signal of 1 KHz and peak voltage 50 v is used to modulate a carrier wave of frequency 1200 KHz and peak voltage 80 V. What is the modulation index ?

A message signal of frequency 10 kHz and peak voltage 10 volt is used to modulate a carrier of frequency 1 MHz and peak voltage 20 volt. Determine (a) modulation index (b) the side bands produced.

A message signal of frequency 10 kHz and peak voltage 10 volt is used to modulate a carrier of frequency 0.5 MHz and peak voltage 100 volt. Determine (i) modulation index (ii) the side bands produced.