This chapter is currently out of syllabus
1
JEE Main 2019 (Online) 12th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
A 100 V carrier wave is made to vary between 160 V and 40 V by a modulating signal. What is the modulation index ?
A
0.5
B
0.6
C
0.4
D
0.3
2
JEE Main 2019 (Online) 11th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
An amplitude modulated signal is plotted below :

JEE Main 2019 (Online) 11th January Evening Slot Physics - Communication Systems Question 83 English

Which one of the following best describes the above signal ?
A
(1 + 9sin (2$$\pi $$ $$ \times $$ 104 t)) sin(2.5$$\pi $$ $$ \times $$ 105t) V
B
(9 + sin (4$$\pi $$ $$ \times $$ 104 t)) sin(5$$\pi $$ $$ \times $$ 105t) V
C
(9 + sin (2$$\pi $$ $$ \times $$ 104 t)) sin(2.5$$\pi $$ $$ \times $$ 105t) V
D
(9 + sin (2.5$$\pi $$ $$ \times $$ 104 t)) sin(2$$\pi $$ $$ \times $$ 104t) V
3
JEE Main 2019 (Online) 11th January Morning Slot
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
An amplitude modulated signal is given by V(t) = 10[1 + 0.3cos(2.2 $$ \times $$ 104 t)] sin(5.5 $$ \times $$ 105 t). Here t is in seconds. The sideband frequencies (in kHz) are, [Given $$\pi $$ = 22/7]
A
892.5 and 857.5
B
89.25 and 85.75
C
1785 and 1715
D
178.5 and 171.5
4
JEE Main 2019 (Online) 10th January Evening Slot
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
The modulation frequency of an AM radio station is 250 kHz, which is 10% of the carrier wave. If another AM station approaches you for license what broadcast frequency will you allot ?
A
2900 kHz
B
2750 kHz
C
2250 kHz
D
2000 kz
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