Electrical Measurements online test on “Voltage to Frequency Converter Type Integrating DVM”.
1. In a voltage to frequency converter type integrated DVM _____________
a) voltage is converted to time
b) voltage is converted to frequency
c) frequency is converted to voltage
d) frequency is converted to time
Answer: a
Clarification: We know that the quantities time and frequency are related to each other. Voltage is converted into time in a voltage to frequency converter type integrating DVM.
2. Input voltage is measured by ____________
a) using a voltmeter
b) counting pulses
c) using a multimeter
d) using an ammeter
Answer: b
Clarification: A pulse train is generated. Their frequency depends on the frequency of the unknown voltage. Number of pulses present in a definite interval are counted. Unknown input voltage is a measure of the pulses generated.
3. What is the main component of an integrating type DVM?
a) diode
b) amplifier
c) op amp
d) oscillator
Answer: c
Clarification: An op amp forms the heart of the integrating type DVM. Op amp is used as an integrator. The input signal is integrated for a fixed interval giving rise to a ramp signal at the output.
4. When input is positive, then output is?
a) growing exponential signal
b) decaying exponential signal
c) positive going ramp
d) negative going ramp
Answer: d
Clarification: The op amp produces a negative going ramp signal for a positive input voltage. Capacitor is discharged after some time and the output returns to zero. The next cycle starts and the output is a sawtooth waveform. Figure shows the output sawtooth waveform.
5. What is the effect of the input signal on the output teeth?
a) directly proportional
b) inversely proportional
c) independent
d) square proportional
