PYQs Based Test - 08 : Sensors and Industrial Instrumentation

The hot junction of a bare thermocouple, initially at room temperature (30°C), is suddenly dipped in molten metal at t = 0s. The cold junction is kept at room temperature. The thermocouple can be modelled as a first-order instrument with time constant of 1.0 s and static sensitivity of 10 μV°/°C. If the voltage, measured across the thermocouple indicates 10.0 mV at t = 1.0 s, then the temperature of the molten metal in °C is ________.

The junction semiconductor temperature sensor shown in the figure is used to measure the temperature of hot air. The output voltage V${}_O$ is 2.1 V. The current output of the sensor is given by I = T μA where T is the temperature in K. Assuming the opamp to be ideal, the temperature of the hot air in °C is approximately _________.

A J-type thermocouple has an output voltage V${}_{\theta }$ = (13650 + 50 θₓ) μV, where θₓ is the junction temperature in Celsius (°C). The thermocouple is used with reference junction compensation, as shown in the figure. The Instrumentation amplifier used has a gain G = 20. If θ${}_{Ref}$ is 1 °C, for an input θₓ of 100 °C, the output Vₒ of the instrumentation amplifier in millivolt is

A resistance temperature detector (RTD) is connected to a circuit, as shown in the figure. Assume the opamp to be ideal. If V₀ = +2.0 V, then the value of x is _________.

The average velocity v of flow of clear water in a 100 cm (inner) diameter tube is measured using the ultrasonic flow meter as shown in the figure. The angle θ is 45°. The measured transit times are t₁ = 0.9950 ms and t₂ = 1.0000 ms. The velocity v (in m/s) in the pipe is (up to one decimal place) ___.