# String efficiency is used for measuring the?

String efficiency is used for measuring the degree of utilization of SCR.

## Related questions

Description : method for improving string efficiency

Last Answer : The Methods of Improving String Efficiency:-   1) By reducing value of ‘m’ or (‘k’) by using longer cross arm. 2) By Making of ‘m’ or (‘k’) equal to zero 3) By grading Insulator. 4) By Using guard ring.

Description : Give the classification of the errors used in measuring instrument & state the reason for their occurrence.

Last Answer : Types of errors in measuring instruments:  A) Gross error: These are due to mistakes on the part of person using the instrument.  B) Systematic Error:  i) Instrumental Error: These ... multiplying factor.  C) Random error: These persist even after gross and systematic errors are removed.

Description : Do you have any string?

Last Answer : There is string in out garage. And it’s string, not twine. I’ve used it to tie a stuffed pork tenderloin. I also have yarn, which is like furry string.

Description : How To Make A String Can Telephone

Last Answer : Materials: 2 tin cans with one hole punched in bottom string Instructions: 1) Prior to the meeting, punch a hole in the bottom of each tin can using a nail and a hammer. 2) Thread string through hole in bottom of can and knot. 3) Pull string taut to ‘talk’ over the telephone.

Description : How to String a Tennis Racquet

Last Answer : How to String a Tennis Racquet If you're a professional tennis player, your racquet is your best friend. It'll need proper care, and one important maintenance task you need to do for it is ... forget to do this maintenance tactic, otherwise you'll find yourself with a faulty racquet in the court!

Description : The number of insulator discs (each rated 11 kV) required in a suspension type insulator string of 220 kV line is

Last Answer : The number of insulator discs (each rated 11kV) required in a suspension type insulator string of 220 kV line is 16

Description : Write a short note on Measuring Flask

Last Answer : Measuring Flask : Flask is laboratory vessels (container). The flask is made of plastic or glass. They are of different sizes and shapes. In school laboratory, 50ml, 100ml, 250ml, 500ml & 1000ml ... of different sizes and shapes. In laboratory 10ml to 25 ml pipette of glass or plastic are used.

Description : What are the test and measuring instrument required in an Electrical depots?

Last Answer : Ans. Following are the test and measuring instruments required in an Electrical depots. a. Test lamp b. Line Tester c. Continuity tester d. Volt meter e. Ammeter f. Earth megger g. Megger h. Lux meter i. Power analyzer j. Infrared thermometer

Description : Electrical Measuring Instruments

Last Answer : Electrical Measuring Instruments

Description : calibration and the need of calibration for measuring instruments.

Last Answer : Calibration - It is a process of estimating the value of a quantity by comparing that quantity with a standard quantity.    Need of calibration: - Calibration defines the accuracy and ... aim of calibration is to minimize any measurement uncertainty by ensuring the accuracy of test equipment.

Description : Explain the essential toques in analog type measuring instruments.

Last Answer : List of torques in analog instruments:  1. Deflecting torque  2. Controlling / Restraining torque.  3. Damping torque.  1. Deflecting torque: To create deflection proportional to ... the speed higher will be the damping torque bringing the pointer to the equilibrium position quickly.

Description : State two purposes of calibration of measuring instruments.

Last Answer : Purposes of calibration of measuring instruments: - The purpose of calibration is to ensure that readings of an instrument are consistent with other instruments. It is also important in determining the ... will need to be calibrated periodically to make sure it can function properly and safely.

Description : List three types of errors in measuring instruments. Give reasons of occurring for any one of them.

Last Answer : Types of errors in measuring instruments:  A) Gross error: These are due to mistakes on the part of person using the instrument.  B) Systematic Error: i) Instrumental Error: These ... multiplying factor.  C) Random error: These persist even after gross and systematic errors are removed.

Description : Define following terms related to measuring instruments: i) Sensitivity ii) Selectivity.

Last Answer : i) Sensitivity: It is the ratio of the change in output signal to the change in input signal of quantity being measured.  ii) Selectivity: It is the term to describe fulfillment of the requirements of measurement by an instrument to be suitable for use in a given situation.

Description : Describe spring control method of producing controlling torque in measuring instrument. Write any two properties required for spring material.

Last Answer : A)Spring control method: As shown in the figure, the inner ends of the both springs are attahced to the spindle, while outer end of upper spring is attached to the lever and outer ... of spring material: 1.Non Magnetic material 2.Low specific resistance 3.Low temperature coefficient of resistance

Description : Name the different torque and their function in measuring instrument.

Last Answer : List of torques in analog instruments:  1. Deflecting torque  2. Controlling / restraining torque.  3. Damping torque.  1. Deflecting torque:  - To create deflection of pointer ... .  - Bring the pointer to standstill quickly.  - To minimize oscillations about final position.

Description : List out any four effects of electric current used in measuring instruments & write name of meter working on it.

Last Answer : Effects of Electric Current used in measuring instruments:  1. Magnetic Effect: PMMC and Moving Iron type Ammeters, voltmeter and Dynamometer type wattmeters etc.  2. Electromagnetic induction ... . Electrostatic effect: Voltmeters.  5. Hall Effect: Flux meter, Poynting vector wattmeter.

Description : What arc the errors occurring in measuring devices due to stray magnetic field and temp '? Explain how to compensate them.

Last Answer : 1. Error due to stray magnetic fields-   Main magnetic field gets disturbed by external magnetic fields known as stray magnetic fields.  2. Compensation technique   To avoid this error, ... resistance alloy having a negligible resistance temp coefficient in the ratio of 1:10 for pressure coil

Description : Explain magnetic effect employed in measuring instrument.

Last Answer : Magnetic Effect:  I) In PMMC meters:  ➢ When a current is passed through a conductor, magnetic field is produced round the conductor. Due to this field when current ... field it experiences a mechanical force.  Examples: Electrodynamometer type instruments, Induction type instrument.

Description : Describe systematic errors in measuring instruments.

Last Answer : Systematic errors: -  ➢ Instrumental Error: These errors are caused due to the mechanical structure of measuring instrument.  a) Inherent shortcomings of instruments: Instrument may read ... or electrostatic fields.  ➢ Observational Error: Parallax errors, incorrect multiplying factor.

Description : State the function of controlling torque in electrical measuring instrument.

Last Answer : Function of controlling torque  1. The function is to opposes the deflection force and increases with the increase in the deflection of the moving system, to limit its movement. 2. and brought ... set a position where the two opposing forces i.e. deflection and controlling forces are equal.

Description : Define: (i) Resolution, (ii) Calibration, with reference to electrical measuring systems.

Last Answer : Resolution The smallest increment in input (the quantity being measured) which can be detected with certainty by an instrument is called its resolution or discrimination.  OR It is ... the measuring instrument with standard instrument to find out the error in the instrument under test.

Description : Why energy meter is integrating type measuring instrument?

Last Answer : Energy Meter is Integrating Type Measuring Instrument: Energy meter is used for measurement of energy, which is obtained by integration (summation) of power supplied over the particular time duration, hence it the integrating type measuring instrument.

Description : List any four effects employed in measuring instruments.

Last Answer : Effects Employed in Measuring Instruments: 1. Magnetic Effect 2. Electromagnetic induction 3. Heating effect 4. Electrostatic effect 5. Hall Effect

Description : When measuring insulation resistance of cables using d.c. source, the galvanometer used should be initially short circuited because  (A) Cables have a low value of capacitance which draws a high ... high value of charging current (D) Cables have a low value of capacitance and initial resistance

Last Answer : When measuring insulation resistance of cables using d.c. source, the galvanometer used should be initially short circuited because Cables have a high value of capacitance which draws a high value of charging current

Last Answer : The desirable static characteristics of a measuring system are accuracy, sensitivity and reproducibility.

Last Answer : For measuring a very high resistance we should use Meggar.

Last Answer : For measuring current at high frequency we should use thermocouple instrument.

Description : Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO

Last Answer : Which of the following thyristors can be used for high frequency of operation? A) TRIAC B) DIAC C) SCR D) GTO

Description : Which circuit is used as amplitude comparator?

Last Answer : Schmitt trigger circuit is used as amplitude comparator.

Description : How is a thyristor used to convert AC to DC?

Description : SEER: Seasonal Energy Efficiency Ratio (SEER)

Last Answer : SEER: Seasonal Energy Efficiency Ratio (SEER), is most commonly used to measure the efficiency of a central air conditioner. The higher the SEER, the more efficient the system OR It is the ... the ratio of total capacity to the total KW energy usage at specific humidity and temperature condition.

Description : State why a transformer always have an efficiency of more than 90%.

Last Answer : As transformer is static device with no moving parts, the losses due to friction & windage are completely absent. Hence transformer has efficiency of more than 90%.

Description :  Compare the salient features of LED and CFL based on: i] Lamp Efficiency ii] Life span

Last Answer : Parameter LED CFL Lamp Efficiency  High (more than 70 lumen per watt) Comparatively less (50-60 lumen per watt) Life span (in working hours) 10000 3000

Description : Define PIV, TUF, ripple factor, efficiency of rectifier.

Last Answer : PIV: Peak Inverse Voltage (PIV) is defined as the maximum negative voltage which appears across non-conducting reverse biased diode. TUF : Transformer Utilization Factor (TUF) is defined as the ratio of DC output ... Efficiency of rectifier: η = DC output power/ AC input power = PLdc / Pac

Description : "Efficiency of thermal power station is low". — Justify.

Last Answer : Justification: Efficiency of thermal power station is low":- Overall efficiency of T.P.P depends upon efficiency of boiler, turbine and alternator. The heat produced due to combustion of coal ... losses in thermal power plant is 71%, So efficiency of thermal power plant is less about 29%

Description : Transformer efficiency

Description : What is the efficiency of Class-B amplifier?  A) 68.50% B) 78.50% C) 88.50% D) 98.50%

Last Answer : What is the efficiency of Class-B amplifier?  A) 68.50% B) 78.50% C) 88.50% D) 98.50%

Description : The overall efficiency of Thermal Power Plant is equal to _______________ .  (A) Regenerative Cycle Efficiency (B) Renkine Cycle Efficiency (C) Carnot cycle efficiency (D) None of the above

Last Answer : The overall efficiency of Thermal Power Plant is equal to Regenerative Cycle Efficiency.

Description : A transformer operates 24 hours day at full -load. It's full -load efficiency is :  (A) equal all day efficiency (B) more than all -day efficiency (C) less than all -day efficiency (D) equal to maximum efficiency

Last Answer : A transformer operates 24 hours day at full -load. It's full -load efficiency is : equal all day efficiency

Description : The rankine cycle efficiency of steam power plant is  (1) 60-80% (3) 30-45% (2) 45-80% (4) 20-30%

Last Answer : The rankine cycle efficiency of steam power plant is 30-45%

Description : Transmission efficiency of a transmission line increases with the

Last Answer : Transmission efficiency of a transmission line increases with the increase in power factor and voltage

Description : For high efficiency of transfer of power, internal resistance of the source should be?

Last Answer : For high efficiency of transfer of power, internal resistance of the source should be less than the load resistance.

Last Answer : The efficiency of diesel locomotives is nearly 20 to 25 percent.

Last Answer : The overall efficiency of steam locomotive is around 5 to 10 percent.

Last Answer : D.C. generators are normally designed for maximum efficiency around full-load.

Last Answer : The condition for maximum efficiency for a D.C. generator is variable losses equal to constant losses.

Last Answer : The range of efficiency for shaded pole motors is 5% to 35%.

Last Answer : The efficiency of a properly designed synchronous motor will usually fall in range 85 to 95%.

Last Answer : Generators for peak load plants are usually designed for maximum efficiency at 50 to 75 percent full load.