ADC (L-23) (ECE) -II BTECH – SEMESTER: II (AY 2024-25)
QUESTION BANK -TEST-1
S.No Question CO’S BTL Max
Mark
1 Explain and detail about dsb-sc? CO1 5 6
2 Explain and detail about ssb-sc? CO1 2 6
3 Explain and detail about vsb? CO1 2 6
4 Advantages and disadvantages of ssb-sc? CO2 2 6
5 Advantages and disadvantages of dsb-sc? CO2 2 6
6 A 400 watt carrier is modulated to a depth of 80%.calculate the total power in the CO1 2 5
modulation wave?
7 A broadcast transmitter radiates 20 kilowatts when the modulation percentage is CO1 2 5
75.how much of this is carrier power?also calculate the power of each sidebands?
8 The total anteena current of an AM transmitter is 5A.if modulation index is 0.6 CO1 4 5
calculate the antenna current when only the carrier is sent?
9 When the modulation percentage is 75,an AM transmitter produces 10KW.How
much of this is carrier power?
CO2 2 5
10 A 1000khz carrier is simultaneously modulated with 300hz,800hz,and 1KHZ audio
sine waves.what will be the frequencies present in the output?
CO2 2 5
11 Explain and detail about angle modulation? CO1 2 3
12 Explain and detail about NBFM? CO1 3
13 Explain and detail about WBFM? CO1 2 3
14 Explain and detail about multitone fm? CO1 5 3
15 Write short notes on transmission bandwidth of fm? CO1 5 3
A 360W carrier is simultaneously modulated by two audio waves with modulation
16 CO1 2 3
percentages of 55 and 65,respectively.what is the total sideband power radiated?
17 When a broadcast AM transmitter is 50 percent modulated,its antenna current is CO1 1 3
12A.what will the current be when the modulation depth is increased to 0.9?
18 Calculate the total modulation index if the carrier wave is amplitude modulated by CO1 2 3
three modulating signals with modulation indices 0.6,0.3 and 0.4 respectively?
When a broadcast AM transmitter is 60 percent modulated,its antenna current is
19 CO1 2 3
16A.what will the current be when the modulation depth is increased to 0.4?
A 460W carrier is simultaneously modulated by two audio waves with modulation
20 CO1 1 3
percentages of 75 and 95,respectively.what is the total sideband power radiated?
21 Explain and detail about types of pulse modulation? CO3 1 3
22 What is meant by PAM? CO3 1 3
23 What is meant by PWM? CO3 2 3
24 What is meant by PPM? CO3 1 3
25 Differences between PAM and PWM? CO3 1 3
QUESTION BANK: QUIZ-1
S.No Question CO’S BTL Max
Mark
1 Quantization noise occurs in? CO1 3 2
2 Which is the greatest disadvantage of Pulse Code Modulation? CO1 2 2
3 Inductance and capacitance of a line is 0.8 μH⁄m and 32 pF⁄m. Find Z0? CO1 2 2
4 Pulse communication system that is inherently highly immune to noise is CO2 1 2
5 What the main advantage of PCM? CO2 1 2
Calculate power in each sideband, if power of carrier wave is 176W and
there is 60% modulation in amplitude modulated signal?
a) 13.36W
b) 52W
6 CO1 1 1
c) 67W
d) 15.84W
Answer:D
For 100% modulation, power in each sideband is ________ of that of
carrier
a) 50%
b) 70%
7 c) 60% CO1 1 1
d) 25%
Answer: D
Overmodulation results in ________________
a) Distortion
b) Weakens signal
8 c) Strengthens the signal CO1 1 1
d) provides immunity to noise
Answer: A
The maximum power efficiency of an AM modulator is?
a) 25%
b) 33%
9 c) 66% CO1 1 1
d) 100%
Answer: B
Noise performance of a square law demodulator of AM signal is?
a) Better than that of synchronous detector
b) Weaker than that of synchronous detector
10 c) Better than that of envelope detector CO1 2 1
d) Weaker than that of envelope detector
Answer: a
11 For getting 100% modulation, carrier amplitude should ________ CO1 2 1
a) exceed signal amplitude
b) be equal to signal amplitude
c) be lesser than signal amplitude
d) be equal to 0
Answer: B
For 100% modulation, total power is?
a) same as the power of unmodulated signal
b) twice as the power of unmodulated signal
12 c) four times as the power of unmodulated signal CO1 2 1
d) one and half times as the power of unmodulated signal
Answer: D
An AM signal is represented by x(t) = (30 + 2Sin(700πt)) Cos(2πt x
102t)V. What is the value of modulation index?
a) 0.7
13 b) 0.066 CO1 2 1
c) 0.341
d) 0.916
Answer: B
An AM signal is represented by x(t) = (30 + 2Sin(700πt)) Cos(2πt x
102t)V. Carrier power of the wave is?
a) 555W
14 b) 675W CO1 2 1
c) 450W
d) 310W
Answer: C
10An AM signal is represented by x(t) = (30 + 2Sin(700πt)) Cos(2πt x
102t)V. Find the total power of amplitude modulated wave?
a) 453W
b) 675W
15 c) 789W CO1 2 1
d) 451W
Answer: D
Distance between direct broadcasting satellite and earth’s surface is
________
a) 4500km
16 b) 33000km CO1 1 1
c) 5200km
d) 36000km
Answer: D
17 UHF stands for ________ CO1 2 1
a) Ultra High Electric Field
b) Ultraviolet High Frequency
c) Ultra High Frequency
d) Ultra High Magnetic Field
Answer: C
What is the ITU designation range for VHF?
a) 30 to 300 Kilohertz
b) 300 to 3000 Kilohertz
18 c) 30 to 300 Megahertz CO1 1 1
d) 3 to 30 Megahertz
Answer: C
Effective noise at high frequencies is ________
a) Johnson noise
b) Flicker noise
19 c) transit-time noise CO1 2 1
d) Partition noise
Answer: C
VHF stands for ________
a) very high frequency
b) very high electric field
20 c) very high magnetic field CO1 2 1
d) very high electromagnetic field
Answer: A
