Do all PLCs have to have power to operate?

Do all PLCs have to have power to operate?
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What are advantages of PLCs over RTUs?

Description : What are advantages of PLCs over RTUs?

Last Answer : Answer: Advantages of Programmable Logic Controllers (PLCs) are they can be used for general purpose can easily set for verity of functions. Some of the advantages of PLCs over RTUs are: PLCs are reliable, cheap, flexible compared to RTUs, sophisticated control and troubleshooting in PLC is easier.

How does an uninterruptible power supply operate?

Description : How does an uninterruptible power supply operate?

Last Answer : An uninterruptible power supply (or UPS) operates, in most cases, as a specialized battery for the computer. The computer will be plugged into the UPS battery. And when the power goes down or surges, the UPS will take over and supply power at the proper voltage.

The winch shown in the illustration will not operate in any speed in the lowering direction and at an abnormal speed in 'first point hoist'. The possible cause is that _______________. EL-0102 A. contactor coil '3M' has many shorted turns B. resistor 'R8-A2' has an open C. contacts '1M' in the power circuit are badly corroded D. master switch contacts 'MS6' have weak springs

Description : The winch shown in the illustration will not operate in any speed in the lowering direction and at an abnormal speed in 'first point hoist'. The possible cause is that _______________. EL-0102 A. ... '1M' in the power circuit are badly corroded D. master switch contacts 'MS6' have weak springs

Last Answer : Answer: B

Why is it desirable to operate paralleled AC generators at the same power factor? A. Circulating currents are kept to a minimum. B. Field excitation losses are kept to a minimum. C. Generator rotors will have a lesser tendency to hunt. D. Because a power factor increase will decrease kilowatt output.

Description : Why is it desirable to operate paralleled AC generators at the same power factor? A. Circulating currents are kept to a minimum. B. Field excitation losses are kept to a minimum. C. Generator ... will have a lesser tendency to hunt. D. Because a power factor increase will decrease kilowatt output.

Last Answer : Answer: A

Power necessary to operate the horn relay shown in the illustration ____________. EL-0093 A. comes from each station's magneto B. is supplied from a 115 volt source C. is conducted through the relay's contacts D. also lights lamps 'R' and 'T'

Description : Power necessary to operate the horn relay shown in the illustration ____________. EL-0093 A. comes from each station's magneto B. is supplied from a 115 volt source C. is conducted through the relay's contacts D. also lights lamps 'R' and 'T'

Last Answer : Answer: A

Power necessary to operate the horn shown in the illustration _____________. EL-0093 A. comes from each station's magneto B. is supplied from a 115 volt source C. is conducted through a relay coil D. also lights lamps 'R' and 'T'

Description : Power necessary to operate the horn shown in the illustration _____________. EL-0093 A. comes from each station's magneto B. is supplied from a 115 volt source C. is conducted through a relay coil D. also lights lamps 'R' and 'T'

Last Answer : Answer: B

Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one armature winding acted on by three identical but separate systems of rotating magnets. C. All three-phase alternators are designed to operate with a 0.8 leading power factor. D. The three phases always provide power to the load through three sets of slip rings and brushes.

Description : Which of the following statements is true concerning all three-phase alternators? A. Each has three separate but identical armature windings acted on by one system of rotating magnets. B. Each has one ... The three phases always provide power to the load through three sets of slip rings and brushes.

Last Answer : Answer: A

The purpose of the capacitor within component 'B' of the circuit shown in the illustration is to ____________. EL-0081 A. prolong the life of the component's contacts B. discharge the neon within the envelope C. counteract the inductive reactance in the circuit D. store power to operate the circuit should 'D' open

Description : The purpose of the capacitor within component 'B' of the circuit shown in the illustration is to ____________. EL-0081 A. prolong the life of the component's contacts B. discharge the neon within ... the inductive reactance in the circuit D. store power to operate the circuit should 'D' open

Last Answer : Answer: A

What is antenna bandwidth? A. Antenna length divided by the number of elements B. The angle between the half-power radiation points C. The angle formed between two imaginary lines drawn through D. The frequency range over which an antenna can be expected to operate satisfactorily

Description : What is antenna bandwidth? A. Antenna length divided by the number of elements B. The angle between the half-power radiation points C. The angle formed between two imaginary lines drawn through D. The frequency range over which an antenna can be expected to operate satisfactorily

Last Answer : D. The frequency range over which an antenna can be expected to operate satisfactorily

With regard to the physics of power systems used operate robots, which statement or statements are most correct? a) hydraulics involves the compression of liquids b) hydraulics involves the compression of air c) pneumatics involve the compression of air d) chemical batteries produce AC power

Description : With regard to the physics of power systems used operate robots, which statement or statements are most correct? a) hydraulics involves the compression of liquids b) hydraulics involves the compression of air c) pneumatics involve the compression of air d) chemical batteries produce AC power

Last Answer : c) pneumatics involve the compression of air

With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power

Description : With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power

Last Answer : C : pneumatic involves the compression of air

With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power

Description : With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power

Last Answer : C : pneumatic involves the compression of air

With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power

Description : With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power

Last Answer : C : pneumatic involves the compression of air

With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power

Description : With regard to the physics of power systems used operate robots, which statement or statements are most correct? A : hydraulics involves the compression of liquids B : hydraulics involves the compression of air C : pneumatic involves the compression of air D : chemical batteries produce AC power

Last Answer : C : pneumatic involves the compression of air

Power tillers operate most satisfactory with? 1. Rotary tillage 2. Plough 3. Transport carts 4. reapers

Description : Power tillers operate most satisfactory with? 1. Rotary tillage 2. Plough 3. Transport carts 4. reapers

Last Answer : ans 1

Which component of seed drill is used for transmit power to operate seed dropping mechanism. a) Frame b) Transport wheel c) Seed box d) Covering device

Description : Which component of seed drill is used for transmit power to operate seed dropping mechanism. a) Frame b) Transport wheel c) Seed box d) Covering device

Last Answer : Transport wheel

Power tillage operate most satisfactory with A. Rotary tillage B. Plough C. Transport carts D. Reapers

Description : Power tillage operate most satisfactory with A. Rotary tillage B. Plough C. Transport carts D. Reapers

Last Answer : Rotary tillage

Power tillers operate most satisfactory with? A. Rotary tillage C. Plough B. Transport carts D. Reapers

Description : Power tillers operate most satisfactory with? A. Rotary tillage C. Plough B. Transport carts D. Reapers

Last Answer : Rotary tillage

Air blast circuit breakers for 400 kV power system are designed to operate in (a) 100 microsecond (b) 50 millisecond (c) 0.5 sec (d) 0.1 sec

Description : Air blast circuit breakers for 400 kV power system are designed to operate in (a) 100 microsecond (b) 50 millisecond (c) 0.5 sec (d) 0.1 sec

Last Answer : (b) 50 millisecond

Burden of a protective relay is the power (a) required to operate the circuit breaker (b) absorbed by the circuit of relay (c) developed by the relay circuit (d) none of the above

Description : Burden of a protective relay is the power (a) required to operate the circuit breaker (b) absorbed by the circuit of relay (c) developed by the relay circuit (d) none of the above

Last Answer : (b) absorbed by the circuit of relay

What meters operate from their own power sources?

Description : What meters operate from their own power sources?

Last Answer : Self-excited.

What meters operate from their own power sources?

Description : What meters operate from their own power sources?

Last Answer : Self-excited.

It takes 500 watts to operate a machine whose power output is 480 watts. Which of the following is the efficiency of the machine? Is it w) 20% x) 48% y) 96% z) 98%

Description : It takes 500 watts to operate a machine whose power output is 480 watts. Which of the following is the efficiency of the machine? Is it w) 20% x) 48% y) 96% z) 98%

Last Answer : ANSWER: Y -- 96%

To reverse the direction of rotation of a three-phase AC induction motor, do one of the following: w) reverse any two of the three-phase connections x) change the frequency of the applied AC power y) operate the motor below the stall torque at very high slip z) none of the above

Description : To reverse the direction of rotation of a three-phase AC induction motor, do one of the following: w) reverse any two of the three-phase connections x) change the frequency of the applied AC power y) operate the motor below the stall torque at very high slip z) none of the above

Last Answer : ANSWER: W -- REVERSE ANY TWO OF THE THREE-PHASE CONNECTIONS 

For power factor correction, synchronous motors operate at?

Last Answer : For power factor correction, synchronous motors operate at no-load and greatly over-excited fields.

Air blast circuit breakers for 400 kV power system are designed to operate in?

Last Answer : Air blast circuit breakers for 400 kV power system are designed to operate in 50 millisecond.