PYQs Based Test - 08 : Sensors and Industrial Instrumentation

A p-type semiconductor strain gauge has a nominal resistance of 1000 Ω and a gauge factor of +200 at 25°C. The resistance of the strain gauge in ohms when subjected to a strain of +10⁻⁴ m/m at the same temperature is __________ Ω.

Given: Density of mercury is 13,600 kg/m³ and acceleration due to gravity is 9.81 m/s². Atmospheric pressure is 101 kPa. In a mercury U-tube manometer, the difference between the heights of the liquid in the U-tube is 1 cm. The differential pressure being measured in pascal is ______ (rounded off to the nearest integer).

The capacitance Cₓ of a capacitive type sensor is (1000 x) pF, where x is the input to the sensor. As shown in the figure, the sensor is excited by a voltage 10 sin (100π t) V. The other terminal of the sensor is tied to the input of a high input impedance amplifier through a shielded cable, with shield connected to ground. The cable capacitance is 100 pF. The peak of the voltage V${}_A$ at the input of the amplifier when x = 0.1 (in volts) is

A liquid level measurement system employing a radio-isotope is mounted on a tank as shown in the figure. The absorption coefficient of water for the radiation is 7.7 m${}^{\text{–}1}$. If the height of water in the tank is reduced from 100 mm to 90 mm, the percentage change in the radiation intensity received by the detector, neglecting absorption of the radiation by air, is __________ %.

In the strain gauge bridge circuit given below, R₁ = R₃ = R (1 − x) and R₂ = R₄ = R (1 + x), where R is 350 Ω. The voltage sources vₛ and vₙ represent the dc excitation and the undesired noise/interference, respectively. The value of capacitor C in microfarad that is required to ensure that the output across a and b is low-pass filtered with a cutoff frequency of 150 Hz is ________.