This chapter is currently out of syllabus
1
JEE Main 2021 (Online) 26th August Evening Shift
+4
-1
Out of Syllabus
A transmitting antenna at top of a tower has a height of 50 m and the height of receiving antenna is 80 m. What is range of communication for Line of Sight (LoS) mode?

[use radius of earth = 6400 km]
A
45.5 km
B
80.2 km
C
144.1 km
D
57.28 km
2
JEE Main 2021 (Online) 25th July Morning Shift
+4
-1
Out of Syllabus
In amplitude modulation, the message signal

Vm(t) = 10 sin (2$$\pi$$ $$\times$$ 105t) volts and

Carrier signal

VC(t) = 20 sin(2$$\pi$$ $$\times$$ 107 t) volts

The modulated signal now contains the message signal with lower side band and upper side band frequency, therefore the bandwidth of modulated signal is $$\alpha$$ kHz. The value of $$\alpha$$ is :
A
200 kHz
B
50 kHz
C
100 kHz
D
0
3
JEE Main 2021 (Online) 22th July Evening Shift
+4
-1
Out of Syllabus
What should be the height of transmitting antenna and the population covered if the television telecast is to cover a radius of 150 km? The average population density around the tower is 2000/km2 and the value of Re = 6.5 $$\times$$ 106 m.
A
Height = 1241 m

Population covered = 7 $$\times$$ 105
B
Height = 1731 m

Population covered = 1413 $$\times$$ 105
C
Height = 1800 m

Population covered = 1413 $$\times$$ 108
D
Height = 1600 m

Population covered = 2 $$\times$$ 105
4
JEE Main 2021 (Online) 18th March Morning Shift
+4
-1
Out of Syllabus
Match List - I with List - II.

List - I

(a) 10 km height over earth's surface

(b) 70 km height over earth's surface

(c) 180 km height over earth's surface

(d) 270 km height over earth's surface

List - II

(i) Thermosphere

(ii) Mesosphere

(iii) Stratosphere

(iv) Troposphere
A
(a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)
B
(a)-(i), (b)-(iv), (c)-(iii), (d)-(ii)
C
(a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
D
(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
EXAM MAP
Medical
NEET