IndiaBix - Measurement, Conversion and Control
c
Holding current for an SCR is best described as A. the minimum current required for turn-off B. the current required before an SCR will turn on C. the amount of current required to maintain conduction D. the gate current required to maintain conduction
b
RTDs are typically connected with other fixed resistors A. in a pi configuration B. in a bridge configuration C. and variable resistors D. and capacitors in a filter-type circuit
d
Temperature sensing can be achieved by the use of A. thermocouples B. RTDs C. thermistors D. All of the above
a
The change in value of an analog signal during the conversion process produces what is called the A. quantization error B. resolution error C. Nyquist error D. sampling error
a
The connections to a thermocouple A. can produce an unwanted thermocouple effect, which must be compensated for B. produce an extra desirable thermocouple effect C.must be protected, since highvoltages are present D. produce an extra desirable thermocouple effect and must be protected, since high voltages are present
a
The output voltage of a typical thermocouple is A. less than 100 mV B. greater than 1 V C. Thermocouples vary resistance, not voltage. D. None of the above
c
The purpose of compensation for a thermocouple is A. to decrease temperature sensitivity B. to increase voltage output C. to cancel unwanted voltage output of a thermocouple D. used for high-temperature circuits
c
The resistive change of a strain gauge A. is based on the weight placed upon it, but can be many thousands of ohms B. is usually no more than 100 Ω C. is based on the gauge factor, but is typically less than an ohm D. has a positive temperature coefficient
b
The silicon-controlled rectifier can be turned off A. by a negative gate pulse B. by forced commutation C. with the off switch D. when the breakover voltage is exceeded
b
What device is similar to an RTD but has a negative temperature coefficient? A. Strain gauge B. Thermistor C. Negative-type RTD D. Thermocouple
d
What is the moving part of a linear variable differential transformer? A. Primary B. Secondary C. Diaphragm D. Core
a
What is the zero-voltage switch used for? A. To reduce radiation of high frequencies during turn-on of a high current to a load B. To control low-voltage circuits C. To provide power to a circuit when power is lost D. For extremely low-voltage applications
a
Which of the following performance specifications applies to a sample-and-hold circuit? A. Aperture time B. Aperture droop C. Feedback D. Acquisition jitter
