This set of Embedded Systems Multiple Choice Questions & Answers (MCQs) focuses on “Errors of ADC technique”.

1. Which signal is sampled at regular intervals for the purpose of ADC?
a) analog signal
b) digital signal
c) quantised signal
d) sampled signal

Explanation: The analog signal is sampled at regular intervals for the analog to digital conversion. Each sample is then quantised to divided by a given value in order to identify the number of approximate analogue value.

2. Which factor depends on the quantisation error?
a) number of error
b) number of bits
c) size of error
d) conversion process

Explanation: The quantisation error depends on the number of bits which is used to represent the analogue vale.

3. Which is the first type of error caused during the conversion process?
a) sampling error
b) interrupt signal
c) counter error
d) quantisation error

Explanation: The quantisation error is the first type of error caused in the conversion process. This error is caused because the samples are converted to a slightly higher value instead of zero.

4. Which of the following defines the number of samples that are taken in the time period?
a) sample size
b) sample nature
c) sample rate
d) sample frequency

Explanation: The sample rate is defined by the number of samples that are taken in a time period. The sample rate is usually measured in Hertz. It can determine the speed of the conversion device itself.

5. Which of the following can determine the speed of conversion device itself?
a) sample rate
b) sampled data
c) sample size
d) sample nature

Explanation: The sample rate determines the various aspect of the conversion process and one such is the conversion speed.

6. Which of the following can determine the maximum frequency that can be converted?
a) sample frequency
b) sample rate
c) sample size
d) sample nature

Explanation: The sample rate can determine the maximum frequency that can be converted as per the Nyquist theorem. The theorem states that the minimum sampling rate frequency should be twice the maximum frequency of the analog signal.

7. Which term determines the random timing error?
a) jitter
b) quantisation error
c) sample error
d) delay

Explanation: Jitter is a random timing error. Jitter can cause irregular sampling errors.

8. Which of the following introduce a phase error?
a) conversion time
b) sampling rate
c) sample size
d) sample nature

Explanation: The conversion time always introduces a phase error. The conversion time will delay the digital output and hence introduce a phase error.

9. Which of the following can generate an interrupt?
a) timer
b) trigger
c) delay
d) counter

Explanation: The timer can generate an interrupt to the processor at the rate of sampling frequency.

10. Which filter is used for filtering out the high frequency components?
a) bandpass filter
b) band reject filter
c) analogue filter
d) digital filter

Explanation: The higher frequency components can be filtered out by using an analog filter after sampling.

11. Which theorem describes the sampling rate with the frequency of the analogue signal?
a) Nyquist theorem
b) Bayes theorem
c) Sampling theorem
d) Parseval’s theorem