11. Which of the following can switch the current by a make or break contact?
A. transistor
B. relay
C. buffer
D. fet
Answer: B
The relays are a kind of switching power in which the logic signal is used to energize the relay. The relay contacts are broken or made accordingly and help in switching the current.
12. Which of the following generates a back EMF?
A. relay
B. buffer
C. transistor
D. FET
Answer: A
The relay generates a back voltage across its terminals when the logic output switches from a high to a low state.
13. Which of the following is used to avoid the back EMF in the relay?
A. resistor
B. capacitor
C. inductor
D. diode
Answer:d
In order to get rid of the back EMF which is generated by the relay, a diode is connected across the terminals which operate in the reverse bias so that nothing can harm the relay.
14. Which of the following can provide a speed control technique in the DC motor interfacing?
A. PCM
B. DPCM
C. ADPCM
D. PWM
Answer: D
The pulse width modulation can provide a speed control technique in the DC motor interfacing by changing its mark/space ratio.
15. Which of the following possesses some loops for providing timing functions?
A. hardware
B. software
C. timer
D. counter
Answer: B
In the software system, certain loops perform the timing functions. A program is created to switch the motor on and it will start counting through a delay loop. When the count is finished, the motor is switched off. In the second delay loop, it can determine the motor-off period.
16. Which signal is sampled at regular intervals for the purpose of ADC?
A. analog signal
B. digital signal
C. quantized signal
D. sampled signal
Answer: A
The analog signal is sampled at regular intervals for the analog to digital conversion. Each sample is then quantized to divided by a given value in order to identify the number of approximate analog values.
17. Which factor depends on the quantization error?
A. number of error
B. the number of bits
C. size of the error
D. conversion process
Answer: B
The quantization error depends on the number of bits which is used to represent the analog value.
18. Which is the first type of error caused during the conversion process?
A. sampling error
B. interrupt signal
C. counter error
D. quantization error
Answer: D
The quantization 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.
19. 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
Answer: C
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.
20. Which of the following can determine the speed of the conversion device itself?
A. sample rate
B. sampled data
C. sample size
D. sample nature
Answer: A
The sample rate determines the various aspect of the conversion process and one such is the conversion speed.
