Q1:

For AM receiver the standard Intermediate frequency is

Q2:

The maximum power efficiency of an AM modulator is.

Q3:

Which of the following analog modulation scheme requires the minimum transmitted power and minimum channel band width?

Q4:

Which one of the following is an indirect way of generating FM?

Q5:

VSB modulation is preferred in TV because

Q6:

Consider the following statements:

1 The bandwidth of AM depends on the BW of message signal.

2. The bandwidth of AM depends on the modulation index.

3. The BW of WBFM, for all practical purposes, is proportional to amplitude of the carrier.

Of these the correct statements are:

Q7:

A signal having modulation depth of 0.4 and 0.5 in a multi tone modulation AM. What is the overall modulation depth?

Q8:

A narrow band FM signal approximately defined by $S(t)=A_c\mathrm{Cos}\left(2\pi f_{c}t\right)-\beta A_c\mathrm{Sin}\left(2\pi f_{c}t\right)\mathrm{Sin}\left(2\pi f_{m}t\right)$

What is the ratio of the maximum to the minimum value of the envelope?

Q9:

A message signal m(t) is recovered from a modulated DSB signal by 1^st multiplying it by a local sinusoidal carrier of $\mathrm{Cos}\left({\omega }_{c}t+\varphi \right)$ and then passing through a low pass filter, the resultant output is--------------------.

Q10:

The input signal to an AM modulator is periodic triangular signal with zero average value. When the modulation index is increased from zero to one, the power increases by-----------%

Q11:

Assertion (A): Narrow band FM signal has LSB 180 degree out of phase as that of USB.

Reason (R): Narrow band FM signal contains a carrier component and two side band components.

Q12:

An audio signal, 15 Sin$\left(2\pi 1500t\right)$amplitude modulates 60 Sin $\left(2\pi {10}^{6}t\right)$. The modulation index will be

Q13:

An angle – modulated signal with carrier frequency ${\omega }_C=2\pi \times {10}^5$is described by the equation $\varphi \left(t\right)=10\mathrm{Cos}\left({\omega }_{C}t+5\mathrm{Sin}3000t+10\mathrm{Sin}2000\pi t\right)$

The deviation ratio is approximately equal to

Q14:

When the modulating frequency is doubled, the modulation index is halved, and the modulating voltage remains constant. The modulation system is

Q15:

The signal m(t) as shown is applied both to a phase modulator (with K_p as the phase constant) and a frequency modulator with (K_f as the frequency constant) having the same carrier frequency.

The ratio K_p/K_f(in rad/Hz) for the same maximum phase deviation is.