Basics of Transducers MCQ Quiz in मल्याळम - Objective Question with Answer for Basics of Transducers - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

Telemeter:

• A telemeter is a device used to remotely measure any quantity. It consists of a sensor, a transmission path, and a display, data recording, or control device.
• Telemeters are the physical devices used in telemetry.
• Electronic devices are widely used in telemetry and can be wireless or hard-wired, analog or digital. Other technologies are also possible, such as mechanical, hydraulic and optical.

Telemetry:

• Telemetry is the collection of measurements or other data at remote points and their automatic transmission to receiving equipment for monitoring.
• The word is derived from the Greek roots tele - "remote", and metron - "measure".
• Systems that need external instructions and data to operate require the counterpart of telemetry, telecommand.
• Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio, ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a telephone or computer network, optical link or other wired communications like power line carriers.
• Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data.
• It is also used to track the movements of wild animals that have been tagged with radio transmitters, and to transmit meteorological data from weather balloons to weather stations.

Analog transducer: It converts the input signal into an output signal, which is a continuous function of time.

Ex: Thermistor, strain gauge, LVDT, thermocouple

Discrete transducer: It converts the input signal into the output signal, in the form of pulses i.e. it gives the discrete output.

Ex: Encoder, digital resolvers, digital tachometers, hall effect sensors, limit switches

Encoder:

It is a digital transducer which generates pulses corresponding to the angular rotation of the shaft.

They are further classified into two category

• Incremental encoder
• Absolute type optical encoder

Incremental encoder

It generates equally spaced pulses base on angular rotation of shaft

Absolute type optical encoder

sIt generates directly binary logic based on angular rotation of the shaft.

Capacitive transducer:

• A capacitive transducer is a passive transducer that works on the principle of variable capacitances.
• It is used to measure physical quantities such as displacement, pressure, etc.

Characteristics of a Capacitive transducer:

The transfer function of a capacitive transducer is given by:

\( T(s)={V_{out}(s) \over V_{in}(s)} = {(jω )^2 \over \sqrt{(1)^2+(jω )^2 }}\)

At ω = 0:

|T(s)| = 0

At ω = ∞ :

|T(s)| = 1

Plotting the frequency response of the capacitive transducer, we get:

Hence, the characteristics produced by a capacitive transducer are non-linear in nature.

• A transducer is a electric device that is used to convert one form of energy into another form.
• A transducer which works on the principle of electromagnetic induction or transduction mechanism is called an inductive transducer.
• In inductive transducer the basic principle is that self-inductance of a single coil or the mutual inductance between two coils is changed by a quantity that is to be measured.
• Inductive transducers may be of  self-generating type or passive type.
• Self generating transducer uses the principle of fundamental electric generator. It doesn't require an external power and they produce analog voltage or current when stimulated by some physical form of energy.
• Passive transducer requires an external power and output is measure of some variation such as resistance, capacitance.

The correct answer is option 4.

Transducers are used to convert a physical parameter to an electrical signal. Common examples of transducers include microphones, loudspeakers, thermometers, position, and pressure sensors, etc.

A transformer is a device that transfers electric energy from one alternating-current circuit to one or more other circuits, either increasing (stepping up) or reducing (stepping down) the voltage.

A speaker is a device for converting electrical energy into acoustical signal energy that is radiated into a room or open air.

The correct answer is option '1'.

Concept:

Microphone:

• It is basically an meant for conversion of sound waves into equivalent electrical waves. 
• It is used at transmitting end.
• In this any input acoustic wave is converted into electrical wave.

The types of microphones are

1. ​Crystal microphone
2. Carbon microphone
3. Dynamic and ribbon microphone
4. Capacitor microphone
5. Wireless microphone

loudspeaker:

• It takes the electrical signal as input and translates it back into vibrations to create sound.
• It is an electromagnetic device.
• It is connected at receiving end.
• It helps to prevent sound waves emiited from rear to mix with the sound waves from front.
• 180 degrees out of phase component of rear waveform will cancel front waveform component.
• It is more prevalent at low frequencies.
   

It is divided into two types

• Moving coil type.
• Electrostatic type.

A simple Microphone Speaker circuit is shown in the figure below:

Telemeter:

• A telemeter is a device used to remotely measure any quantity. It consists of a sensor, a transmission path, and a display, data recording, or control device.
• Telemeters are the physical devices used in telemetry.
• Electronic devices are widely used in telemetry and can be wireless or hard-wired, analog or digital. Other technologies are also possible, such as mechanical, hydraulic and optical.

Telemetry:

• Telemetry is the collection of measurements or other data at remote points and their automatic transmission to receiving equipment for monitoring.
• The word is derived from the Greek roots tele - "remote", and metron - "measure".
• Telemetry allows data flow only in a single direction, that is from source to receiver.
• Systems that need external instructions and data to operate require the counterpart of telemetry, telecommand.
• Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio, ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a telephone or computer network, optical link or other wired communications like power line carriers.
• Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data.
• It is also used to track the movements of wild animals that have been tagged with radio transmitters, and to transmit meteorological data from weather balloons to weather stations.

D/A converter is not a component of the data-acquisition system.

The various components of the Data Acquisition system are: •

Transducers: The emf obtained from the transducers like thermocouples, strain gauge bridges, piezo-electric devices, and photosensitive devices which are proportional to the quantity being measured are used in DAS.

Signal Conditioner: Signal conditioners are used to transform the output of the transducer to the desired magnitude or form required by the next stage of the data acquisition system. It produces the required conditions in the transducers so that they work properly 

Multiplexer: A multiplexer is used to accept multiple analog inputs and connecting them sequentially to one measuring input. The same transmission channel is used for transmitting more than one quantity with the help of a multiplexer. It uses either TDM (Time-division multiplexing) or FTD (Frequency division multiplexing) for this purpose.

Calibrating equipment: Pre-calibration and post calibrations are used before and after each test. There is millivolt calibration of all input circuits and shunt calibration of all bridge type transducer circuits.

Integrating equipment: Integrating equipment is used for integral or summation of a quantity. Digital techniques are normally used for this purpose.

Visual display devices: Panel mounted meters, numerical displays, single or multichannel CROs and storage type CROs are used as visual display devices

Analog recorders: Analog recorders are used for recording data in analog form. It includes strip recorders, magnetic tape recorders, and CRO with photograph's equipment 

Analog computers:
(i) An analog computer is used as a data reduction device i.e. reducing the data recorded by the transducers and sensors. The output voltage of an analog computer is either recorded in analog form or converted into a digital form for recording and further computations.

(ii) Analog computations are less accurate than digital computations but, it Is more economical to compute data by analog methods using analog computers than by digital computations

Transducer:​

• Active transducers are those which do not require any power source for their operation.
• They work on the energy conversion principle.
• They produce an electrical signal proportional to the input (physical quantity).
• Piezoelectric, thermocouple, and photovoltaic cell transducers all are active transducers.

Hygrometer:

• A hygrometer is an instrument used to measure relative humidity.
• Humidity is the measure of the amount of moisture in the air.
• A psychrometer is an example of a hygrometer.
  ​

Radiation pyrometer:

• The main theory behind a radiation pyrometer is that the temperature is measured through the naturally emitted heat radiation by the body. This heat is known to be a function of its temperature.
• The radiation pyrometer has an optical system including a lens, a mirror, and an adjustable eyepiece.
• The heat energy emitted from the hot body is passed on to the optical lens, which collects it and is focused on the detector with the help of the mirror and eyepiece arrangement.
• Thus, the heat energy is converted to its corresponding electrical signal by the detector and is sent to the output temperature display device.
• The temperature of the sun is measured by using a radiation pyrometer.

A transducer that makes use of air gap change is referred to as Reluctance type

Telemeter:

• A telemeter is a device used to remotely measure any quantity. It consists of a sensor, a transmission path, and a display, data recording, or control device.
• Telemeters are the physical devices used in telemetry.
• Electronic devices are widely used in telemetry and can be wireless or hard-wired, analog or digital. Other technologies are also possible, such as mechanical, hydraulic and optical.

Telemetry:

• Telemetry is the collection of measurements or other data at remote points and their automatic transmission to receiving equipment for monitoring.
• The word is derived from the Greek roots tele - "remote", and metron - "measure".
• Telemetry allows data flow only in a single direction, that is from source to receiver.
• Systems that need external instructions and data to operate require the counterpart of telemetry, telecommand.
• Although the term commonly refers to wireless data transfer mechanisms (e.g., using radio, ultrasonic, or infrared systems), it also encompasses data transferred over other media such as a telephone or computer network, optical link or other wired communications like power line carriers.
• Many modern telemetry systems take advantage of the low cost and ubiquity of GSM networks by using SMS to receive and transmit telemetry data.
• It is also used to track the movements of wild animals that have been tagged with radio transmitters, and to transmit meteorological data from weather balloons to weather stations.