134. Thermistor is a bulk semiconductor device having temperature coefficient of resistance which is
A. high and negative
B. low and negative
C. high and positive
D. low and positive

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135. The device used to measure flow of air around an aeroplane is
A. venturimeter
B. orifice
C. rotameter
D. anemometer

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136. In a pitot tube
A. velocity head is converted into pressure head
B. pressure head is converted into velocity head
C. velocity head is converted into datum head
D. differential pressure is produced across the tube

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137. Hot wire anemometer is used to measure
A. pressure of gauges
B. liquid discharge
C. very low pressures
D. gas velocities

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138. The function of the reference electrode in a pH meter is
A. to measure average pH value
B. to produce a constant voltage
C. to provide temperature compensation
D. to produce a constant current

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139. Piezo-electric quartz crystal can be used to measure
A. temperature
B. velocity
C. acceleration
D. flow

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140. Main advantage of semiconductor strain gauge over resistive strain gauge is its
A. high sensitivity
B. low sensitivity
C. smaller size
D. better ruggedness

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