Standard AM and Single Tone AM

Standard AM and Single Tone AM

Review Quiz

Multiple Choice

Bandwidth of standard AM with carrier frequency equal to 500kHz and Maximum frequency content in message equal to 7 kHz.

• 493 kHz

• 507 kHz

• 14 kHz

• 1000 kHz

Multiple Choice

Minimum frequency content of standard AM with carrier frequency equal to 500kHz and Maximum frequency content in message equal to 7 kHz.

• 493 kHz

• 507 kHz

• 14 kHz

• 1000 kHz

Multiple Choice

A single Tone AM system has the following Time Domain Expression s(t). Given the message amplitude is equal to 3V, Choose the correct option

 $s\left(t\right)=\left[1+0.21\cos\left(6000\pi t\right)\right]\cos\left(1000000\pi t\right)$  

• Carrier Amplitude = 1V, Modulation index = 0.07, Amplitude Sensitivity = 21%, Message Frequency = 300Hz, Carrier Frequency = 1kHz, Signal is overmodulated

• Carrier Amplitude = 1V, Modulation index = 0.21, Amplitude Sensitivity = 0.07, Message Frequency = 3kHz, Carrier Frequency = 500kHz, Signal is not overmodulated
  
  

Multiple Choice

A single Tone AM system has the following Time Domain Expression s(t). Given the message amplitude is equal to 3V, Choose the correct option

 $s\left(t\right)=\left[1+0.21\cos\left(6000\pi t\right)\right]\cos\left(1000000\pi t\right)$  

•  $A_{\max}=1.21V\ and\ A_{\min}=0.79V$  
  

•  $A_{\max}=1.07V\ and\ A_{\min\ }=\ 0.93V$  
  

Multiple Choice

A single Tone AM system has the following Time Domain Expression s(t). Given the message amplitude is equal to 3V, The carrier power is __________. (Let R = 1 ohm)

 $s(t)=[1+0.21\cos(6000πt)]\cos(1000000πt)$  

• 0.5 watts

•  $\frac{1}{\sqrt{2}}$  watts

• 1 watts

Multiple Choice

A single Tone AM system has the following Time Domain Expression s(t). Given the message amplitude is equal to 3V, The power in upper side frequency (503 kHz) is _____. (Let R = 1 ohm)

 $s(t)=[1+0.21\cos(6000πt)]\cos(1000000πt)$  

• 5.5125 mW

• 0.125 mW

• 0.25 mW

Multiple Choice

A single Tone AM system has the following Time Domain Expression s(t). Given the message amplitude is equal to 3V, The total power is _____. (Let R = 1 ohm)

 $s(t)=[1+0.21\cos(6000πt)]\cos(1000000πt)$  

• 511.025 mW

• 11.025 mW

• 16.025 mW

Multiple Choice

 $Carrier\ Power\ =\ \frac{1}{2}A_c^2$ 

 $Upper\ Side\ Frequency\ Power\ =\ \frac{1}{8}\mu^2A_c^2$   $Lower\ Side\ Frequency\ Power\ =\ \frac{1}{8}\mu^2A_c^2$  

The Total Power is

•  $A_c^2\left(\frac{1}{2}+\frac{1}{4}\mu^2\right)$  

•  $\frac{A_c^2\mu^2}{16}$  

Multiple Choice

Consider power efficiency of a single tone AM system is defined as the ratio of the total side band power to the total power in the modulated wave. Then the power efficiency if modulation index is equal to

 $\mu$  is

•  $\frac{\left(1+\mu\right)^2}{\left(1-\mu\right)^2}$  

•  $\frac{1}{8}\mu^2$  

•  $\frac{\mu^2}{\left(2+\mu^2\right)}$  

Multiple Choice

The power efficiency of a single tone AM system for percentage modulation values 0%, 20% and 100% respectively are

• 33.33%, 1.96% and 0%

• 0, 1.96% and 33.33%