MCQOPTIONS
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MCQOPTIONS
This section includes 7 Mcqs, each offering curated multiple-choice questions to sharpen your Digital Signal Processing Questions and Answers knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
What is the basic relationship between the spectrum o f the real band pass signal x(t) and the spectrum of the equivalent low pass signal xl(t)? |
| A. | X (F) = \(\frac{1}{2} [X_l (F-F_c)+X_l^* (F-F_c)]\) |
| B. | X (F) = \(\frac{1}{2} [X_l (F-F_c)+X_l^* (F+F_c)]\) |
| C. | X (F) = \(\frac{1}{2} [X_l (F+F_c)+X_l^* (F-F_c)]\) |
| D. | X (F) = \(\frac{1}{2} [X_l (F-F_c)+X_l^* (-F-F_c)]\) |
| Answer» E. | |
| 2. |
What is the expression for low pass signal component us(t) that can be expressed in terms of samples of the bandpass signal? |
| A. | \(\sum_{n=-∞}^∞ (-1)^{n+r+1} x(2nT^{‘}-T^{‘}) \frac{sin(π/(2T^{‘})) (t-2nT^{‘}+T^{‘})}{(π/(2T^{‘}))(t-2nT^{‘}+T^{‘})}\) |
| B. | \(\sum_{n=-∞}^∞ (-1)^n x(2nT^{‘}) \frac{sin(π/(2T^{‘})) (t-2nT^{‘})}{(π/(2T^{‘}))(t-2nT^{‘})}\) |
| C. | All of the mentioned |
| D. | None of the mentioned |
| Answer» B. \(\sum_{n=-∞}^∞ (-1)^n x(2nT^{‘}) \frac{sin(π/(2T^{‘})) (t-2nT^{‘})}{(π/(2T^{‘}))(t-2nT^{‘})}\) | |
| 3. |
What is the expression for low pass signal component uc(t) that can be expressed in terms of samples of the bandpass signal? |
| A. | \(\sum_{n=-∞}^∞ (-1)^{n+r+1} x(2nT^{‘}-T^{‘}) \frac{sin(π/(2T^{‘})) (t-2nT^{‘}+T^{‘})}{(π/(2T^{‘}))(t-2nT^{‘}+T^{‘})}\) |
| B. | \(\sum_{n=-∞}^∞ (-1)^n x(2nT^{‘}) \frac{sin(π/(2T^{‘})) (t-2nT^{‘})}{(π/(2T^{‘}))(t-2nT^{‘})}\) |
| C. | All of the mentioned |
| D. | None of the mentioned |
| Answer» C. All of the mentioned | |
| 4. |
According to the sampling theorem for low pass signals with T1=1/B, then what is the expression for us(t) = ? |
| A. | \(\sum_{m=-∞}^∞ u_c (mT_1) \frac{sin(\frac{π}{T_1}) (t-mT_1)}{(\frac{π}{T_1})(t-mT_1)}\) |
| B. | \(\sum_{m=-∞}^∞ u_s (mT_1-\frac{T_1}{2}) \frac{sin(\frac{π}{T_1}) (t-mT_1+\frac{T_1}{2})}{(π/T_1)(t-mT_1+\frac{T_1}{2})}\) |
| C. | \(\sum_{m=-∞}^∞ u_s (mT_1-\frac{T_1}{2}) \frac{sin(\frac{π}{T_1}) (t-mT_1-\frac{T_1}{2})}{(\frac{π}{T_1})(t-mT_1-\frac{T_1}{2})}\) |
| D. | \(\sum_{m=-∞}^∞ u_c (mT_1) \frac{sin(\frac{π}{T_1}) (t+mT_1)}{(\frac{π}{T_1})(t+mT_1)}\) |
| Answer» C. \(\sum_{m=-∞}^∞ u_s (mT_1-\frac{T_1}{2}) \frac{sin(\frac{π}{T_1}) (t-mT_1-\frac{T_1}{2})}{(\frac{π}{T_1})(t-mT_1-\frac{T_1}{2})}\) | |
| 5. |
According to the sampling theorem for low pass signals with T1=1/B, then what is the expression for uc(t) = ? |
| A. | \(\sum_{m=-∞}^∞ u_c (mT_1)\frac{sin(\frac{π}{T_1}) (t-mT_1)}{(π/T_1)(t-mT_1)}\) |
| B. | \(\sum_{m=-∞}^∞ u_s (mT_1-\frac{T_1}{2}) \frac{sin(\frac{π}{T_1}) (t-mT_1+T_1/2)}{(\frac{π}{T_1})(t-mT_1+\frac{T_1}{2})}\) |
| C. | \(\sum_{m=-∞}^∞ u_c (mT_1)\frac{sin(\frac{π}{T_1}) (t+mT_1)}{(\frac{π}{T_1})(t+mT_1)}\) |
| D. | \(\sum_{m=-∞}^∞ u_s (mT_1-\frac{T_1}{2}) \frac{sin(\frac{π}{T_1}) (t+mT_1+\frac{T_1}{2})}{(\frac{π}{T_1})(t+mT_1+\frac{T_1}{2})}\) |
| Answer» B. \(\sum_{m=-∞}^∞ u_s (mT_1-\frac{T_1}{2}) \frac{sin(\frac{π}{T_1}) (t-mT_1+T_1/2)}{(\frac{π}{T_1})(t-mT_1+\frac{T_1}{2})}\) | |
| 6. |
What is the final result obtained by substituting Fc=kB-B/2, T= 1/2B and say n = 2m i.e., for even and n=2m-1 for odd in equation x(nT)= \(u_c (nT)cos2πF_c nT-u_s (nT)sin 2πF_c nT\)? |
| A. | \((-1)^m u_c (mT_1)-u_s\) |
| B. | \(u_s (mT_1-\frac{T_1}{2})(-1)^{m+k+1}\) |
| C. | None |
| D. | \((-1)^m u_c (mT_1)- u_s (mT_1-\frac{T_1}{2})(-1)^{m+k+1}\) |
| Answer» E. | |
| 7. |
The frequency shift can be achieved by multiplying the band pass signal as given in equation |
| A. | x(t) = \(u_c (t) cos2π F_c t-u_s (t) sin2π F_c t\) by the quadrature carriers cos[2πFct] and sin[2πFct] and lowpass filtering the products to eliminate the signal components of 2Fc. |
| B. | True |
| C. | False |
| Answer» B. True | |