# MCQs on Types of Transducers

1 - Question

What are transducers?
a) They convert power from one form to another
b) They convert work from one form to another
c) They convert work to power
d) They convert energy from one form to another
Explanation: Transducer are devices that convert energy from one form to another. This energy can be either mechanical energy, light energy, heat energy or any other forms of energy.

2 - Question

Active transducer do not require any type of additional power source for an operation.
a) True
b) False
Explanation: Active transducers do not require any additional power source for converting the energy from one form to another as they work on the principle of energy conversion. One such example of active transducer is thermocouple.

3 - Question

What type of energy conversion does a piezoelectric transducer perform?
a) It converts mechanical energy to sound energy
b) It converts sound energy to mechanical energy
c) It converts mechanical energy to electrical energy
d) It converts electrical energy to mechanical energy
Explanation: A piezoelectric transducer converts mechanical energy to electrical energy. They are generally used to detect a knock or any impulsive force. They are also used in electronic drum pads to detect the impulse provided by the drumsticks.

4 - Question

Pirani Gauge is an example of which type of transducer?
a) Pressure transducer
b) Temperature transducer
c) Light transducer
d) Mechanical transducer
Explanation: Pirani Gauge is a pressure transducer. It’s a thermal conductivity gauge used to detect pressure in vacuum conditions. It was named after a German physicist “Marcello Stefano Pirani” who invented it in 1906.

5 - Question

The IC LM35 is used as which type of sensor?
a) Pressure sensor
b) Temperature sensor
c) Light sensor
d) Mechanical sensor
Explanation: The LM35 IC manufactured by Texas Instruments is used as a temperature sensor. The output voltage generated by this IC is linearly proportional to the temperature in Centigrade. The output voltage is directly proportional to the temperature.

6 - Question

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.

7 - Question

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.

8 - Question

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.

9 - Question

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.

10 - Question

In which state of chemical substances does a chemical sensing device work?
a) Solid
b) Liquid
c) Vapour
d) Plasma