1. What is the range of frequency of the waves produced by the Ultrasonic transducer?
a) 20 Kilohertz to several Gigahertz
b) 1 Kilohertz to several Gigahertz
c) 40 Kilohertz to several Megahertz
d) less than 20 Kilohertz
Explanation: Ultrasonic transducers produce frequency ranging from 20 Kilohertz to several Gigahertz. Ultrasounds have a wide range of application in many fields, but majorly they are used for measuring the distance of objects.
2. What is the full form of LVDT with respect to displacement transducer?
a) Linear variable differential temperature
b) Linear variable differential transformer
c) Liquid visible differential transformer
d) Liquified visible differential transformer
Explanation: LVDT stands for Linear variable differential transformer. It is a displacement transducer that converts rectilinear motion to electric signals. They are used widely due to their robustness.
3. What is the effect on properties of LDR when light falls on it?
a) Its resistance remains same
b) Its resistance changes
c) Its capacitance changes
d) Its inductance changes
Explanation: When light falls on LDR (Light dependant resistor) its resistance changes. It is inversely proportional to the intensity of light. When light falls on LDR, the resistance decreases and more current starts to flow through it. It is used to measure the intensity of light.
4. What is measured by a hall effect transducer?
a) Electric flux
b) Electric Field
c) Magnetic field
d) Temperature
Explanation: Hall effect transducers or Hall effect sensor is used for measuring the magnitude of the magnetic field. The output voltage produced by the sensor is directly proportional to the strength of the magnetic field passing through it.
5. In which state of chemical substances does a chemical sensing device work?
a) Solid
b) Liquid
c) Vapour
d) Plasma
Explanation: The chemical sensors detect the chemicals in the vapour form. Most of the chemical sensor are in the form of gas sensors. These sensors are widely used in industries to detect any gas leakage or for automatic fire alarms.
6. What is the nature of resistance to light intensity graph of an LDR (Light dependent resistor)?
a) Increasing
b) Decreasing
c) Parabolic
d) Constant
Explanation: The resistance to light intensity graph of an LDR (Light dependent resistor) has a decreasing nature. As the intensity of the light falling on the LDR (Light dependent resistor) increases, the value of its resistance decreases.
7. What is the absolute error of an observation taken by an ultrasonic sensor which predicts the distance of an object to be 5.1 cm but the actual value is 5 cm?
a) 1.02
b) 0.1
c) 0.01
d) 1
Explanation: Given: Actual Value=5cm
Measured Value=5.1cm
Absolute error=Measured Value-Actual Value
Absolute error=5.1cm-5cm=>0.1cm
8. What is the relative error of an observation taken by an ultrasonic sensor which predicts the distance of an object to be 3.1 cm but the actual value is 3 cm?
a) 1.03
b) 0.1
c) 0.033
d) 1
Explanation: Given: Actual Value=3cm
Measured Value=3.1cm
Absolute error=Measured Value-Actual Value
Absolute error=3.1cm-3cm => 0.1cm
Relative error=Absolute error/Actual value
Relative error=0.1/3=>0.033
9. What is the sensitivity of a sensor if the difference between two alternative output observations is 0.6 and difference between two alternative input observations is 0.2?
a) 3
b) 0.6
c) 0.2
d) 2
Explanation: Given: Change in output=0.6
Change in input=0.2
Sensitivity=Change in output/Change in input
Sensitivity=0.6/0.2=>3
10. What is the nature of resistance to light intensity graph of aB57211P0100M301 thyristor?
a) Increasing
b) Decreasing
c) Parabolic
d) Constant
Explanation: The resistance to temperature graph of a B57211P0100M301 thermistor has a decreasing nature. When the temperature of the B57211P0100M301 increases, then the value of its resistance decreases. And vice versa happens when temperature decreases.