**
Q.1 The system described by
**

is ? |

B) Time-invariant

C) Causal

D) Both linear & Causal

E) None of these

Q.2 A DSB-SC Modulation scheme ?

A) Sends a copy of a carrier

B) Requires more BW than SSB

C) Is ideal for a situation where there is one sender and many receivers

D) All of the above

E) None of these

Q.3 Ideal HPF are not used because

A) They are too expensive

B) They are not causal

C) They require too much BW

D) They can be made directly from LPF

Q.4 If X ( w ) is the Fourier transform of x ( t ) & z ( t ) = - 2 x ( 10 t ) ?

A) The amplitude spectrum of z ( t ) is frequency compressed compared to that of x ( t ).

B) The phase spectrum of z ( t ) is the negative of the phase spectrum of x ( t ).

C) The Nyquist sampling rate for z ( t ) is the same as the Nyquist Sampling rate for x ( t ).

D) z ( w ) will contain impulses at w = ± 10.

E) None of above