MCQOPTIONS
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MCQOPTIONS
This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Control Systems knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
The sinusoid x(t) =6cos10πt is sampled at the rate of 15 Hz and applied to ideal rectangular LPF with cut-off frequency of 10 Hz, then the output of filter contains: |
| A. | Only 10π rad/sec component |
| B. | 10π rad/sec component |
| C. | 10π rad/sec and 20π rad/sec components |
| D. | +10π rad/sec and +20π rad/sec components |
| Answer» C. 10π rad/sec and 20π rad/sec components | |
| 2. |
A digital measuring instrument employs a sampling rate of 100 samples/second. The sampled input x(n) is averaged using the difference equation:Y (n) =[x (n)+x (n-1)+x(n-2)+x(n-4)/4]For a step input, the maximum time taken for the output to reach the final value after the input transition is |
| A. | 20 ms |
| B. | 40 ms |
| C. | 80 ms |
| D. | ∞ |
| Answer» C. 80 ms | |
| 3. |
An LTI system having transfer function s2+1/s2+2s+1 and input x(t) =sin(t+1) is in steady state. The output is sampled at ws rad/s to obtain the final output {y (k)}. Which of the following is true? |
| A. | Y is zero for all sampling frequencies ws |
| B. | Y is non zero for all sampling frequencies ws |
| C. | Y is non zero for ws>2 but zero for ws<2 |
| D. | Y is zero for ws>2 but non zero for ws<2 |
| Answer» B. Y is non zero for all sampling frequencies ws | |
| 4. |
A signal represented by x(t) =5cos 400πt is sampled at a rate 300 samples/sec. The resulting samples are passed through an ideal low pass filter of cut-off frequency 150 Hz. Which of the following will be contained in the output of the LPF? |
| A. | 100 Hz |
| B. | 100 Hz, 150 Hz |
| C. | 50 Hz, 100 Hz |
| D. | 50 Hz, 100 Hz, 150 Hz |
| Answer» B. 100 Hz, 150 Hz | |
| 5. |
Statement (I): Aliasing occurs when the sampling frequency is less than twice the maximum frequency in the signal.Statement (II): Aliasing is a reversible process. |
| A. | Both statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I). |
| B. | Both Statement (I) and Statement (II) are individually true but Statement (II) is not correct explanation of Statement (I) |
| C. | Statement (I) is true but Statement (II) is false |
| D. | Statement (I) is False but Statement (II) is true |
| Answer» D. Statement (I) is False but Statement (II) is true | |
| 6. |
A_DIGITAL_MEASURING_INSTRUMENT_EMPLOYS_A_SAMPLING_RATE_OF_100_SAMPLES/SECOND._THE_SAMPLED_INPUT_X(N)_IS_AVERAGED_USING_THE_DIFFERENCE_EQUATION:?$ |
| A. | =[x (n)+x (n-1)+x(n-2)+x(n-4)/4] For a step input, the maximum time taken for the output to reach the final value after the input transition is |
| B. | 20 ms |
| C. | 40 ms |
| D. | 80 ms |
| Answer» C. 40 ms | |
| 7. |
The_sinusoid_x(t)_=6cos10πt_is_sampled_at_the_rate_of_15_Hz_and_applied_to_ideal_rectangular_LPF_with_cut-off_frequency_of_10_Hz,_then_the_output_of_filter_contains:$# |
| A. | Only 10π rad/sec component |
| B. | 10π rad/sec component |
| C. | 10π rad/sec and 20π rad/sec components |
| D. | +10π rad/sec and +20π rad/sec components |
| Answer» C. 10‚âà√¨‚àö√ë rad/sec and 20‚âà√¨‚àö√ë rad/sec components | |
| 8. |
An LTI system having transfer function s2+1/s2+2s+1 and input x(t) =sin(t+1) is in steady state. The output is sampled at ws rad/s to obtain the final output {y (k)}. Which of the following is true? |
| A. | Y is zero for all sampling frequencies ws |
| B. | Y is non zero for all sampling frequencies ws |
| C. | Y is non zero for ws>2 but zero for ws<2 |
| D. | Y is zero for ws>2 but non zero for ws<2 |
| Answer» B. Y is non zero for all sampling frequencies ws | |
| 9. |
A signal m(t) with bandwidth 500 Hz is first multiplied by a signal g(t). The resulting signal is passed through an ideal low pass filter with bandwidth 1 kHz. The output of the low pass filter would be : |
| A. | Impulse |
| B. | m(t) |
| C. | 0 |
| D. | m(t)del(t) |
| Answer» D. m(t)del(t) | |
| 10. |
A signal represented by x(t) =5cos 400πt is sampled at a rate 300 samples/sec. The resulting samples are passed through an ideal low pass filter of cut-off frequency 150 Hz. Which of the following will be contained in the output of the LPF?$ |
| A. | 100 Hz |
| B. | 100 Hz, 150 Hz |
| C. | 50 Hz, 100 Hz |
| D. | 50 Hz, 100 Hz, 150 Hz |
| Answer» B. 100 Hz, 150 Hz | |
| 11. |
A bandpass sampling extends from 4-6 kHz. What is the smallest sampling frequency required to retain all the information in the signal. |
| A. | 1 kHz |
| B. | 2 kHz |
| C. | 3 kHz |
| D. | 4 kHz |
| Answer» E. | |
| 12. |
Increased pulse-width in the flat-top sampling leads to: |
| A. | Attenuation of high frequencies in reproduction |
| B. | Attenuation of low frequencies in reproduction |
| C. | Greater aliasing errors in reproduction |
| D. | No harmful effects in reproduction |
| Answer» B. Attenuation of low frequencies in reproduction | |
| 13. |
Let x(t) be a continuous-time, real valued signal band-limited to F Hz. The Nyquist sampling rate in Hz, For y(t) =x(0.5t) +x(t)-x(2t) is |
| A. | F |
| B. | 2F |
| C. | 4F |
| D. | 8F |
| Answer» D. 8F | |
| 14. |
A band limited signal with a maximum frequency of 5 KHz to be sampled. According to the sampling theorem, the sampling frequency which is not valid is: |
| A. | 5 KHz |
| B. | 12 KHz |
| C. | 15 KHz |
| D. | 20 KHz |
| Answer» B. 12 KHz | |
| 15. |
Statement (I): Aliasing occurs when the sampling frequency is less than twice the maximum frequency in the signal. |
| A. | : Aliasing is a reversible process. |
| B. | Both statement (I) and Statement (II) are individually true and Statement (II) is the correct explanation of Statement (I). |
| C. | Both Statement (I) and Statement (II) are individually true but Statement (II) is not correct explanation of Statement (I) |
| D. | Statement (I) is true but Statement (II) is false |
| Answer» D. Statement (I) is true but Statement (II) is false | |