274. The function x(t) is shown in the figure 10.12. Even and odd parts of a unit-step function u(t) are respectively,1

A. ?1

B.--2 ,12

C., ? x(t)

D.?2 x(t)

275. The power in the signal s(t)= 8 cos (207tt -+ 4 in (15710 is-2-

A.40

B.41

C.42

D.82

276. The output y(t) of a linear time invariant system is related to its input x(t) by the following equation :y(t) = 0.5x (t - td + T) + x(t - td) + 0.5x (t - td - T). The filter transfer function H(D) of such a system is given by

A. (1 + coscoT)Ciwtd

B. (1 + 0.5 coscoT)e-i'td

C. (1 + cos oine-i'td

D. (1 -0.5 cos coT)e--"td

277. For a signal x(t) the fourier transform is X(/). Then the inverse Fourier transform of X(3f + 2) is given by

A. ?2141-2 )

B. ?1 (1) e-J4nt/33x 3

C. 3x(3t)e4' t

D. x(3t + 2)

278. A device with input x(t) and output y(t) is characterized by : y(t)= x2(t).An FM signal with frequency deviation of 90 kHz modulating signal bandwidth of 5 kHz is applied to this device. The bandwidth of the output signal is

A. 370 kHz

B. 190 kHz

C. 380 kHz

D. 95 kHz

279. A carrier is phase modulated (PM) with frequency deviation of 10 kHz by a single input 1 1 2 3 tone frequency of 1 kHz. If the single tone frequency is increased to 2 kHz, assuming that phase deviation remains unchanged, the bandwidth of the PM signal is

A. 21 kHz.

B. 22 kHz

C. 42 kHz

D. 44 IcHz

280. Let x(t) 4---3 X (j CD) be Fourier Transform pair. The Fourier Transform of the signal x(5t - 3) in terms of X (jal) is given as j3co

A. - e 5 x 5

B. !1 j3w e e 5 x =

C. 1 e-i3e) x (L) )

D. - e x Ijko1 j(0 )f

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