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The CORRECT answer is (a) span

Explanation: The TOTAL OPERATING range of the transducer is called span of the transducer. OFFSET is the output that will exist when it should be zero. Drift is basically the change in a signal over long period of time.

The correct ANSWER is (b) False

Best explanation: Hysteresis ischange in output with the same value of INPUT but with a different history of input variation. Hysteresis is observed when the input/output characteristics for a transducer are different for increasing inputs than for decreasing outputs. It results when some of the ENERGY applied for increasing inputs is not recovered when the input DECREASES.

Right option is (B) operational amplifier

Explanation: Operational amplifier is not a part of PASSIVE filters. It is a part of an active filter. Passive components are resistors capacitors and inductors. Active filters use OPAMPS in ADDITION to passive components in order to obtain better performance.

Right answer is (a) low frequency response

For explanation: The BIOELECTRIC signals in medical science CONTAINS components of EXTREMELY low frequency. THUS the amplifiers must also have a low frequency response. The response should be down to less than ONE hertz which is a very frequent requirement.

Correct ANSWER is (b) electrochemical

Explanation: Home BLOOD glucose detection SENSOR works on the principle of electrochemical. The biosensor in this instrument relies upon ENZYMES that recognise and catalyze reactions of glucose with the generation of redox – active species that are detected electrochemically.

Right choice is (c) phosphor BRONZE

Explanation: Phosphor bronze is USED to make diaphragm to measure pressure. The motion of diaphragm is measured in terms of electric SIGNALS. TOURMALINE , barium titanate and zirconate titanate are piezo electric materials.

The correct choice is (b) PRESSURE electricity

To elaborate: Piezo-electricity is pressure electricity. The piezo ELECTRIC effect is a property of natural crystalline substance to DEVELOP electric potential along a crystallographic axis in response to the movement of charge as a result of MECHANICAL deformation.

The CORRECT CHOICE is (d) hyperbolically

The explanation: By moving ONE plate of the capacitor with respect to the other, the capacitance will vary inversely with respect to the plate separation. This will give a hyperbolic displacement capacitance characteristic. This is how variable capacitance is EMPLOYED as displacement transducers.

The correct answer is (B) resistance temperature detector

Explanation: RTD STANDS for Resistance Temperature Device. It is a passive SENSOR and requires current excitation to produce an output voltage. RTD has very low temperature COEFFICIENT. Voltage DROP across RTD is much larger than thermocouple output voltage.

Right choice is (a) True

For EXPLANATION: Yes, on APPLYING electricity to the piezo-electric material mechanical deformation OCCURS in the material. The piezo electric effect is a property of natural crystalline substance to develop electric POTENTIAL along a crystallographic axis in RESPONSE to the movement of charge as a result of mechanical deformation.

Right answer is (b) variable INDUCTANCE

Explanation: LVDT works on the principle of variable inductance. It has three coils namely the PRIMARY COIL which is the CENTER coil. The other two are called the SECONDARY coils so connected that their outputs are equal in magnitude but opposite in phase.

The correct choice is (b) noise

Easy explanation: Noise is the unwanted signal at the output DUE EITHER to internal sources or to interference. OFFSET is the output that will EXIST when it should be ZERO. The threshold of the transducer is the smallest change in measurant that will result in a measurable change in the transducer output.

Correct CHOICE is (B) passive transducers

The best I can explain: Passive transducers are transducers that require energy to translate CHANGES due to the measurand. Active transducers convert one form of energy directly into another. For EXAMPLE photovolatic cell in which LIGHT energy is converted into electrical energy.

Correct option is (b) higher capacitance

Explanation: To achieve the low FREQUENCY RESPONSE required for MEDICAL applications, the amplifier must have LARGE VALUES of coupling capacitance. In all RC-coupled amplifiers, low frequency response is limited by the reluctance of the coupling capacitors. The response should be down to less than one hertz which is a very frequent requirement.

The correct choice is (a) glucose oxidase

Easy explanation: The chemical REACTION of glucose with oxygen is catalyzed in the PRESENCE of glucose oxidase. In the presence of glucose oxidase as a catalyst, the glucose and oxygen REACT and GLUCONIC acid is produced as by product. Hydrogen perioxide (H2O2) is ALSO produced in some amount.

The CORRECT option is (c) THERMOCOUPLE

For EXPLANATION: This arrangement is called thermocouple. The junction at a higher TEMPERATURE in thermocouple is termed as measuring junction. The junction at lower temperature in the thermocouple is called the reference temperature.

The correct choice is (a) True

The best EXPLANATION: True. Active filters use opamps in addition to passive COMPONENTS in ORDER to obtain better performance. Operational AMPLIFIERS are frequently used as the gain blocks in active filters. Passive components are resistors capacitors and inductors.

Right choice is (b) False

The best I can explain: HOME blood glucose measurement DEVICES measure the glucose level through invasive method. There is a small needle at the TIP of the machine that PIERCES the SKIN to take blood sample. This blood is then undergoes electrochemical reactions and the glucose level is determined.

Right answer is (b) conversion of light energy to ELECTRICAL energy

The best I can explain: Photoelectric transducers are based on the principle of conversion of light energy into electrical energy. This is done by causing the radiation to FALL on a photosensitive ELEMENT and measuring the electrical CURRENT so GENERATED with a sensitive galvanometer directly or after suitable amplification.

Right answer is (d) 273 K

For explanation I would SAY: The lower temperature junction in THERMOCOUPLE is maintained at 273 K (0^0C). The junction at lower temperature in the thermocouple is called the reference temperature. The junction at HIGHER temperature in thermocouple is termed as measuring junction.

The correct choice is (d) Accidental hypothermia

The BEST I can EXPLAIN: Sudden involuntary drop in BODY core temperature below 35*C (95*F) is called Accidental hypothermia. In this, the body temperature drops very QUICKLY. If not treated on time can lead to patients death.

Correct choice is (d) settling TIME

The best explanation: Settling time is the time for the SENSOR to reach a stable output once it is TURNED on. Frequency response is the change of transfer FUNCTION with frequency, both in magnitude and in phase. The total operating range of the transducer is CALLED span of the transducer.

Right choice is (d) transducer

To EXPLAIN: TRANSDUCERS convert biochemical events into measurable signals. They provide the means for DETECTING the biochemical changes inside the body. Particularly BIOSENSORS are employed for this PURPOSE.

Right choice is (b) False

To ELABORATE: Optical fiber SENSORS are ELECTRICALLY passive and consequently immune to electromagnetic DISTURBANCES. They are geometrically flexible and corrosion resistant. They can be miniaturized and are most suitable for telemetry applications.

The correct option is (a) Rt = Ro(1+ɑt)

For explanation I would SAY: The resistance Rt of a metallic CONDUCTOR at any TEMPERATURE t is given by Rt = Ro(1+ɑt). Ro is the resistance at 0*C. ɑ is temperature coefficient of resistivity.

Correct choice is (a) variable resistance

Explanation: POTENTIOMETER works on the principle of variable resistance. The resistance between two terminals of this device is related to the linear or angular displacement of a SLIDING tape ALONG a resistance ELEMENT. When the fixed terminals of the potentiometer are connected to the power supply. Either AC or dc, output voltage at the wiper varies with the displacement of the object.

Correct option is (d) spectroscopic Sensors

Easy explanation: Spectroscopic Sensors is the one that detects the ANALYTE species DIRECTLY through their characteristic SPECTRAL properties. In these sensors, the optical fibre functions only as a light guide, CONVEYING light from the source to the SAMPLING area and from the sample to the detector. Here, the light interacts with the species being sensed.

Correct CHOICE is (b) telethermometers

Easy explanation: The instruments which give a direct reading of the TEMPERATURE at the thermistor position are known by the name telethermometers. This is because of their ABILITY to use leads which are hundreds of feet long without a significant decrease in accuracy. The continuous signal is ALSO suitable for recording without AMPLIFICATION.

Correct option is (a) selenium

For explanation I would SAY: Photovoltaic or barrier layer cells usually consist of a semiconducting substance, which is generally selenium deposited on a metal base which may be iron and which acts as one of the ELECTRODES. The semiconducting substance is COVERED with a thin layer of SILVER or gold deposited by cathodic deposition in a vacuum. This layer acts as a COLLECTING electrode.