Recent questions tagged control

asked Jun 28, 2020 by anonymous

Draw the labeled block diagram of process control system and explain each block.

Last answer: Explanation - Process control system consists of process or plant, sensor, error detector, automatic Controller, actuator or control element. 1) Process or plant- process means some manufacturing sequence ... process which changes the process variable. Output of this block is denoted by u .

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139 views 1 answer

asked May 3, 2020 by anonymous

Describe control of a single lamp from three places. Draw the relevant circuit diagram.

Last answer: Single lamp control from three places- It consists of two way switches & intermediate switch, the circuit diagram is as shown in figure. We require two 2-way switches and one intermediate switch and a lamp ... position of any one switch is changed, then the lamp will be turned off.

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90 views 1 answer

asked May 3, 2020 by anonymous

State the purpose of lighting control. List the different types of dimmer.

Last answer: Purpose of Lighting Control:- 1. To turn ON or OFF the lamps 2. For dimming: The dimming control permits the adjustment of lighting over a range. 3. For changing the lighting levels ... operated dimmer 6) Triac operated Dimmer 7) PWM (Pulse width modulation) Controlled technique.

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66 views 1 answer

asked May 3, 2020 by anonymous

Illustrate with neat wiring diagram a single lamp control by two point method.

Last answer: Single lamp control by two point method: This system is commonly used for stair case wiring. It consists of two way switches (the switch operates always in one of the two possible positions) the ... the person will change the position of switch S2, so that the lamp will be switched OFF'.

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78 views 1 answer

asked Oct 13, 2019 by anonymous

Speed control of the motor using TRIAC

Last answer: Speed control of the motor using TRIAC: This basic phase triggering circuit uses the triac in series with the motor across an AC sinusoidal supply. The variable resistor, VR1 is used ... meaning that it may not trigger at the exact same point for each positive and negative half cycle.

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210 views 1 answer

asked Aug 6, 2019 by anonymous

Define the following terms : (i) Base Station (ii) Control Channel (iii) Mobile Station (iv) Page

Last answer: i) Base Station: - A fixed station in a mobile radio system used for radio communication with mobile stations. Base stations are located at the center or on the edge of a coverage region ... the page throughout the service area using base stations which broadcast the page on a radio carrier.

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84 views 1 answer

asked Jul 4, 2019 by anonymous

What are the disadvantages of Open loop control system?

Last answer: Open loop control system are less reliable. In open loop control system Optimization is not possible. Open loop control system are less accurate.

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56 views 1 answer

asked Sep 29, 2018 by anonymous

Draw and explain bulk correction method for power factor & control.

Last answer: Bulk correction method for power factor & control: i) Here individual starter controls the capacitors located at distribution panel. ii) Centralized compensation is employed in large industrial plants where many ... capacitor units in steps to maintain P.F. more than preset limit (0.95).

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92 views 1 answer

asked Sep 8, 2018 by anonymous

State the function of following components of a nuclear power station: i) Moderator ii) Shielding iii) Control rod iv) Coolant

Last answer: i) Function of Moderator :- Moderator is to moderate or reduce the speed of fast neutron to help the fission process. ii) Function of sheilding : Shielding is to protect environment, ... from reactor core and transfer it in heat exchanger for producing steam at high pressure and temperature.

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52 views 1 answer

asked Sep 7, 2018 by anonymous

Write function of control rods in nuclear power plant.

Last answer: Function of control rods in nuclear power plant: The function of control rod is to control the chain reaction in reactor core by adjusting its height.

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36 views 1 answer

asked Sep 6, 2018 by anonymous

Write one advantage and one disadvantage each for spring control method and gravity control method.

Last answer: Advantages of Spring Control Method: 1) The spring-controlled meters may be used in any position. 2) In some instruments, springs can be used as current leads. 3) As springs are light in weight ... only. 2) Scale is non-uniform. 3) Control weights add to the weight of instrument.

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363 views 2 answers

asked Sep 6, 2018 by anonymous

State the function of former and control spring in PMMC instrument.

Last answer: Function of Former: To support the coil and provide eddy current damping. Function of Control Spring: To provide control torque or force and in some instruments springs can be used as current leads.

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120 views 1 answer

asked Sep 6, 2018 by anonymous

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

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530 views 1 answer

asked Sep 5, 2018 by anonymous

Explain spring control method with neat diagram.

Last answer: 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 end of ... the springs are twisted in opposite direction to the motion of pointer and produce controlling torque.

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255 views 1 answer

asked Aug 31, 2018 by anonymous

Quality control is aimed at:

Quality control is aimed at: a. Maintaining the desired quality b. Exceeding the desired quality c. Continuously improving the quality d. Following the quality

Last answer: Quality control is aimed at: a. Maintaining the desired quality b. Exceeding the desired quality c. Continuously improving the quality d. Following the quality

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68 views 1 answer

asked May 1, 2018 by anonymous

A control system having unit damping factor will give

A control system having unit damping factor will give (1) Oscillatory response (2) Undamped response (3) Critically damped response (4) No response

Last answer: 1

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591 views 2 answers

asked May 1, 2018 by anonymous

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control

The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque (1) Decreases (2) Increases (3) Remains constant (4) None of the above

Last answer: The speed of a three-phase induction motor is controlled by variable voltage variable frequency control (i.e. keeping V/f constant). As the frequency is reduced, the slip at maximum torque Increases

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121 views 1 answer

asked Apr 30, 2018 by anonymous

A differentiator is not usually used in control system, because it : -

A differentiator is not usually used in control system, because it : - (A) reduces damping (B) increases error (C) reduces gain margin (D) increases input noise

Last answer: A differentiator is not usually used in control system, because it : - increases input noise

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59 views 1 answer

asked Apr 28, 2018 by anonymous

The meter which does not have any component in it to provide control torque is

The meter which does not have any component in it to provide control torque is (A) Electrodynamometer for current measurement (B) Electrodynamometer for voltage measurement (C) Electrodynamometer for power measurement. (D) Electrodynamometer for power factor measurement.

Last answer: The meter which does not have any component in it to provide control torque is Electrodynamometer for power factor measurement.

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119 views 1 answer

asked Apr 28, 2018 by anonymous

A unity negative feedback control system is found to have a gain margin of 20 dB. The Nyquist plot of the

A unity negative feedback control system is found to have a gain margin of 20 dB. The Nyquist plot of the system (A) crosses the real axis at +0.1 (B) crosses the real axis at -0.1. (C) crosses the imaginary axis at -0.1 (D) crosses the imaginary axis at +0.1

Last answer: A unity negative feedback control system is found to have a gain margin of 20 dB. The Nyquist plot of the system crosses the real axis at -0.1.

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98 views 1 answer

asked Apr 28, 2018 by anonymous

Precise control of reactive current flow entering the transmission and distribution systems can be minimized

Precise control of reactive current flow entering the transmission and distribution systems can be minimized by using (A) synchronous condenser (B) static VAR capacitor (C) capacitor bank (D) thyristor switched reactor in parallel with capacitor

Last answer: Precise control of reactive current flow entering the transmission and distribution systems can be minimized by using (A) synchronous condenser (B) static VAR capacitor (C) capacitor bank (D) thyristor switched reactor in parallel with capacitor

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107 views 1 answer

asked Apr 26, 2018 by anonymous

Regulating-transformers are used in power systems for control of

Last answer: Regulating-transformers are used in power systems for control of power flow

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119 views 1 answer

asked Apr 26, 2018 by anonymous

Negative feedback in a closed-loop control system DOES NOT

Negative feedback in a closed-loop control system DOES NOT (A) reduce the overall gain (B) reduce bandwidth (C) improve disturbance rejection (D) reduce sensitivity to parameter variation

Last answer: Negative feedback in a closed-loop control system DOES NOT reduce bandwidth

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119 views 1 answer

asked Apr 26, 2018 by anonymous

The standard for long distance analog signal transmission in process control industry is

The standard for long distance analog signal transmission in process control industry is (A) 4-20 mV (B) 0-20 mA (C) 4-20 mA (D) 0-5 V

Last answer: The standard for long distance analog signal transmission in process control industry is 4-20 mA

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2.5k views 1 answer