JEE Main 2018 (Online) 15th April Evening Slot | Communication Systems Question 89 | Physics

JEE Main 2018 (Online) 15th April Evening Slot

MCQ (Single Correct Answer)

-1

The carrier frequency of a transmitter is provided by a tank circuit of a coil of inductance 49 $$\mu $$H and a capacitance of 2.5 nF. It is modulated by an audio signal of $$12$$ $$kHz.$$ The frequency range occupied by the side bands is :

13482 kHz $$-$$ 13494 kHz

442 kHz $$-$$ 466 kHz

63 kHz $$-$$ 75 kHz

18 kHz $$-$$ 30 kHz

JEE Main 2018 (Online) 15th April Morning Slot

MCQ (Single Correct Answer)

-1

The number of amplitude modulted broadcast stations that can be accomodated in a $$300$$ $$kHz$$ band width for the highest modulating frequency $$15$$ $$kHz$$ will be :

$$20$$

$$15$$

$$10$$

$$8$$

JEE Main 2017 (Online) 9th April Morning Slot

MCQ (Single Correct Answer)

-1

A signal is to be transmitted through a wave of wavelength $$\lambda $$, using a linear antenna. The length l of the antenna and effective power radiated P_eff will be given respectively as :

(K is a constant of proportionality)

$$\lambda $$, P_eff = K $$\left( {{1 \over \lambda }} \right)$$²

$${{\lambda \over 8}}$$, P_eff = K $$\left( {{1 \over \lambda }} \right)$$

$${{\lambda \over 16}}$$, P_eff = K $$\left( {{1 \over \lambda }} \right)$$³

$${{\lambda \over 5}}$$, P_eff = K $$\left( {{1 \over \lambda }} \right)$$$${\left( {{1 \over \lambda }} \right)^{{1 \over 2}}}$$

JEE Main 2017 (Online) 8th April Morning Slot

MCQ (Single Correct Answer)

-1

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.

Modulation index = 5, side frequency bands are at 1400 kHz and 1000 kHz

Modulation index = 5, side frequency bands are at 21.2 kHz and 18.8 kHz

Modulation index = 0.8, side frequency bands are at 1180 kHz and 1220 kHz

Modulation index = 0.2, side frequency bands are at 1220 kHz and 1180 kHz

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