Surprise Quiz - I 20EI252

Digital impulse signal is defined by the sequence

• δ (n) =1.n=00,n<0

• δ (n) =1.n=00,n>0

• δ (n) =1.n=00,n≠0

• δ (n) =1.n≥00,n≠0

In Linear Convolution if y(n)=x(n)*h(n) where x(n) has M values and h(n) has N values then y(n) has

• N+M-1

• N+M

• N/M

• NM

In time scaling property of a signal when μ >1 then the output signal is called as

• expanded signal

• compressed signal

• growing Signal

• decaying signal

A system whose output y(n) at time n depends on any number of the past outputs values

• recursive

• non recursive

• causal

• Time invariant system

Examine whether the system y(n)=x(n)cos(wn) is a linear/non linear and time variant/Invariant system

• linear and time invariant

• linear and time varying

• non linear and time invariant

• non linear and time varying

If X1(k) and X2(k) are the N-point DFTs of X1(n) and x2(n) respectively, then what is the N-point DFT of x(n)=ax1(n)+bx2(n)?

• X1(ak)+X2(bk)

• aX1(k)+bX2(k)

• eakX1(k)+ebkX2(k)

• aX1(k)-bX2(k)

In radix 2 FFT the total number of complex multiplications are

• (N /2)log2N

• N log2N

• (N*N) log2N

• log2(N/2)

The number of additions for 8 point DFT in Direct evaluation method and in FFT method is given by

• 16,24

• 56,24

• 56,19

• 24,68

Which of the following is true regarding the number of computations required to compute an N-point DFT?

• N2 complex multiplications and N(N-1) complex additions

• N2 complex additions and N(N-1) complex multiplications

• N2 complex multiplications and N(N+1) complex additions

• N2 complex additions and N(N+1) complex multiplications

The Circular convolution for the sequences x(n)={1,2,3,4} and h(n)={1,1,1,1}

• {10,11,10,11}

• {9,9 ,9,9}

• {10,9,10,9}

• {9,10,11,12}