What are the different braking of DC machines?

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Dynamic or rheostatic braking,plugging and regenerative braking

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Related questions

What are the different types of DC machines?

Last Answer : Dc machine is classified as   self excited  separately excited  permanent magnet  Self excited Dc motor is further classified as  series ... are classified as  long shunt short shunt

A series wound DC motor has its armature and field connected in series with a resistor. When the motor is disconnected from its power supply, this motor will exemplify __________. A. the proper connections for across the line starting B. the proper connections for an automatic strip heater C. a reversing controller circuit D. dynamic braking

Description : A series wound DC motor has its armature and field connected in series with a resistor. When the motor is disconnected from its power supply, this motor will exemplify __________. A. the ... the proper connections for an automatic strip heater C. a reversing controller circuit D. dynamic braking

Last Answer : Answer: D

Regenerative braking (A) Can be used for stopping a motor. (B) Cannot be easily applied to DC series motors. (C) Can be easily applied to DC shunt motors (D) Cannot be used when motor load has overhauling characteristics.

Description : Regenerative braking (A) Can be used for stopping a motor. (B) Cannot be easily applied to DC series motors. (C) Can be easily applied to DC shunt motors (D) Cannot be used when motor load has overhauling characteristics.

Last Answer : Ans: B Because reversal of Ia would also mean reversal of field and hence of Eb

A DC chopper is used for regenerative braking of a separately excited DC motor. The DC supply

Description : A DC chopper is used for regenerative braking of a separately excited DC motor. The DC supply voltage is 400V. The armature current during regenerative braking is kept constant at 300 A with negligible ripple. For a duty cycle of 60% ... to the DC supply is  (a) 78 kW (b) 58 kW (c) 38 kW (d) 48 kW

Last Answer : 48

Explain in brief how anti-lock braking system works

Description : Explain in brief how anti-lock braking system works

Last Answer : An ABS is a system on motor vehicles which prevents the wheels from locking while braking stopping safely is one of the most important functions a motor vehicle can perform. Diagram: ... to decrease the pressure on the braking circuit, effectively reducing the braking force on that wheel.

Draw and explain the control and power diagram for D.C. injection Braking.

Description : Draw and explain the control and power diagram for D.C. injection Braking.

Last Answer : Circuit Operation  1)Starting & Running - Pressing the start button S2 will energise coil C2 provided the stop button S1 is not pressed and the overload OL2 has not tripped. The retaining contact of C2 ... de-energising C3 and removing DC from the stator. This in turn de-energises the timer coil. 

Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars? A. A grounded commutator bar B. Using improper carbon brushes C. Aligning the front and rear mica V-rings improperly D. An open circuit in the armature

Description : Which of the listed conditions might contribute to very rapid wearing of a DC machine's commutator bars? A. A grounded commutator bar B. Using improper carbon brushes C. Aligning the front and rear mica V-rings improperly D. An open circuit in the armature

Last Answer : Answer: B

Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt field rheostats are interconnected. C. The series fields of both generators are connected in series. D. The equalizer connection parallels the series fields of all machines.

Description : Which of the methods listed is used to maintain the division of load between two compound-wound, DC generators operating in parallel? A. The shunt fields are interconnected. B. The shunt ... generators are connected in series. D. The equalizer connection parallels the series fields of all machines.

Last Answer : Answer: D

Enlist the types of dc machines?

Description : Enlist the types of dc machines?

Last Answer : Answer: D.C. machines are classified into two types 1) separately excited 2) self excited which is further classified into 1)series 2)shunt and 3)compound(which is further classified into cumulative and differential).

Why Does Curving The Pole Faces In A Dc Machines Contributes To A Smoother Dc Output Voltage From It?

Description : Why Does Curving The Pole Faces In A Dc Machines Contributes To A Smoother Dc Output Voltage From It?

Last Answer : For having smoother output voltage from DC machines its commutation must be as ideal as possible. In order to have good commutation the flux density in the air gap must decrease gradually from maximum value under the center of the pole to zero on.

What is the minimum recommended absorption coefficient value for AC and DC rotating machines?

Description : What is the minimum recommended absorption coefficient value for AC and DC rotating machines? 

Last Answer : Tips:  a. IR value decreases some what with an increase I applied voltage. However for machines in good condition substantially the same IR is obtained for any test voltage ... a value which after correction for temperature, may be compared with the recommended minimum value of IR. 

What are the minimum recommended PI values for AC and DC rotating machines?

Description : What are the minimum recommended PI values for AC and DC rotating machines? 

Last Answer : Following minimum recommended PI values criteria is to be followed. a. 1.5 for class – A insulation. b. 2.0 for class – B insulation. c. 2.5 for class – F insulation. 

Fractional pitch windings are used in DC machines to

Description : Fractional pitch windings are used in DC machines to (A) Reduce copper losses (B) Improve cooling (C) Increase the generated emf (D) Reduce sparking

Last Answer : Fractional pitch windings are used in DC machines to Reduce sparking

In dc machines, the armature windings are placed on the rotor because of the necessity for

Description : In dc machines, the armature windings are placed on the rotor because of the necessity for  (1) electromechanical energy conversion (2) generation of voltage (3) commutation (4) development of torque

Last Answer : 3  Commutation

The introduction of interpoles in between the main poles improves the performance of DC machines because:

Description : The introduction of interpoles in between the main poles improves the performance of DC machines because: (A) the interpole produces additional flux to augment the torque developed (B) the flux waveform ... of the armature is removed (D) a counter emf is induced in the coil undergoing commutation

Last Answer : The introduction of interpoles in between the main poles improves the performance of DC machines because: a counter emf is induced in the coil undergoing commutation

What can cause squeaking from my brakes while driving but not while braking?

Description : What can cause squeaking from my brakes while driving but not while braking?

Last Answer : I took off my front tire to look at my pads on that one. Well they look ok expect behind my rotor disk the brake pad looks kinda chipped and chopped up? Like its peeling funny and wearing on it ... this a caliper broken? What could be doing that to the brake pad from the other side of the rotor?

Astrophysics question: Are zero braking distance collisions and infinitive forces possible?

Description : Astrophysics question: Are zero braking distance collisions and infinitive forces possible?

Last Answer : No, it is not. F=m*a, where a is acceleration expressed in m/s/s. zero braking distance also means zero deceleration time. deceleration is negative acceleration. So zero deceleration time turns it into m/s/0. Division by zero.

Stopping distance of vehicles : When brakes are applied to a moving vehicle, the distance it travels before stopping is called stopping distance. It is an important factor for road safety and depends on the initial velocity ( v 0 ) and the braking capacity, or deceleration, ?a that is caused by the braking. A car travelling at speed 72km/hr suddenly applies the brake with the deceleration of 5m/s2. Find the stopping distance of the car -Science

Description : Stopping distance of vehicles : When brakes are applied to a moving vehicle, the distance it travels before stopping is called stopping distance. It is an important factor for road safety and depends on ... the brake with the deceleration of 5m/s2. Find the stopping distance of the car -Science

Last Answer : Here u=72 km/hr = 72×10003600m/s=2072×10003600m/s=20 m/s , v=0 a= -5 m/s2 Now using the relation v2=u2+2asv2=u2+2as 0=(20)2+2×(−5)×s0=(20)2+2×(−5)×s s=40ms=40m

Numerical Questions and answers on Motion for Class 9 physics a. What is the distance travelled by the SUV is first 2 seconds? b. What is the braking force at the end of 5 seconds to bring the SUV to a stop within one seconds? -Science

Description : Numerical Questions and answers on Motion for Class 9 physics a. What is the distance travelled by the SUV is first 2 seconds? b. What is the braking force at the end of 5 seconds to bring the SUV to a stop within one seconds? -Science

Last Answer : a. The distance travelled by the SUV is first 2 seconds = Area of ΔABEΔABE =12 AE BE=12 AE BE =12 2 15=15m=12 2 15=15m b. Acceleration will be given by the slope of the line CD a=0−156−5= ... =−15m/s2 Now mass of the SUV =1000 Kg Braking Force will be F=ma=1000 −15=−15000NF=ma=1000 −15=−15000N

What should you do if the wheels slip during braking and the car starts to roll? (Cross Test)

Description : The braking force must be reduced and reversing must be stopped by counter-steering. The braking force must be increased and the tillage must be stopped by counter-steering. When braking with constant force, counter-steering must be stopped.

Last Answer : The braking force must be reduced and the steering must be stopped by counter-steering.

What can be the braking distance of the train?

Description : If he carries 20 wagons of coal, for example, it can slow down quite a bit, right?

Last Answer : I think that the slip section at a speed of 120 km / h was prescribed 700 m, but I no longer remember exactly

What if your vehicle pulls tp one side when braking why?

Description : What if your vehicle pulls tp one side when braking why?

Last Answer : brakes ineffectoive and not properly adjusted

Which lining does most of the braking on a dual-servo brake?

Description : Which lining does most of the braking on a dual-servo brake?

Last Answer : I'm going to say the secondary (facing rearward) lining ondual-servo drum brake does more work than the primary (facingforward) lining because the rear lining is almost always longerthan the front lining to compensate for more wear.

Why In a standard vehicle the braking system transforms the kinetic energy into what?

Description : Why In a standard vehicle the braking system transforms the kinetic energy into what?

Last Answer : What is the answer ?

What American car had the first anti lock braking system?

Description : What American car had the first anti lock braking system?

Last Answer : The 1970 Lincoln Continental was the first American car withABS.

What is dynamic braking used for?

Description : What is dynamic braking used for?

Last Answer : Braking is used to bring the motor to stop quickly or instantly. Braking can be two way broadly. One is mechanical braking. Other method is electrical braking. One of the electrical braking is dynamic braking.

What is Dynamic braking is used for?

Description : What is Dynamic braking is used for?

Last Answer : Braking is used to bring the motor to stop quickly or instantly. Braking can be two way broadly. One is mechanical braking. Other method is electrical braking. One of the electrical braking is dynamic braking.

When the speed of car is doubled, then what will be the braking force of the car to stop it in the same distance? (1) four times (2) two times (3) half (4) one-fourth

Description : When the speed of car is doubled, then what will be the braking force of the car to stop it in the same distance? (1) four times (2) two times (3) half (4) one-fourth

Last Answer : (1) four times Explanation: Brake force, also known as Brake Power, is a measure of braking power of a vehicle. Suppose a car whose mass is 'x' and is braked from a speed of y km/hr to come to ... the car is four times the original speed i.e. '4v'. Note that all the parameters remain to be same.

The progressive operation of the contactors marked 'A' provide the winch shown in the illustration with __________. EL-0102 A. accumulation B. dynamic braking C. acceleration D. regenerative braking

Description : The progressive operation of the contactors marked 'A' provide the winch shown in the illustration with __________. EL-0102 A. accumulation B. dynamic braking C. acceleration D. regenerative braking

Last Answer : Answer: C

The purpose of 'R6' in the winch circuit shown in the illustration is to _______________. EL-0102 A. maintain dry conditions within the winch brake box B. keep the series field current at a low value during 'fourth and fifth point lowering' C. act as the armature dynamic braking load to assist the winch in stopping D. limit the armature current during lowering operation with heavy loads

Description : The purpose of 'R6' in the winch circuit shown in the illustration is to _______________. EL-0102 A. maintain dry conditions within the winch brake box B. keep the series field current at ... to assist the winch in stopping D. limit the armature current during lowering operation with heavy loads

Last Answer : Answer: C

A motor using a rheostat in the motor circuit to vary the speed is called a ____________. A. squirrel-cage induction motor B. regenerative braking motor C. wound-rotor induction motor D. synchronous motor

Description : A motor using a rheostat in the motor circuit to vary the speed is called a ____________. A. squirrel-cage induction motor B. regenerative braking motor C. wound-rotor induction motor D. synchronous motor

Last Answer : Answer: C

What Is Meant By Regenerative Braking?

Description : What Is Meant By Regenerative Braking?

Last Answer : When the supply is cutt off for a running motor, it still continue running due to inertia. In order to stop it quickly we place a load(resitor) across the armature winding and the motor should ... and due to load the motor stops quickly.This type of breaking is called as Regenerative Breaking .

What is meant by dynamic braking?

Description : What is meant by dynamic braking?

Last Answer : Dynamic braking of electric motors occurs when the energy stored in the rotating mass is dissipated in an electrical resistance. This requires the motor to operate as a generator to convert this stored energy into electrical.

What is meant by regenerative braking?

Description : What is meant by regenerative braking?

Last Answer : When the supply is cut off for a running motor, it still continue running due to inertia. In order to stop it quickly we place a load (resistor) across the armature winding and the motor should ... and due to load the motor stops quickly. This type of breaking is called as Regenerative Breaking .

In a braking test, a vehicle travelling at 36 km ph was stopped at a braking distance of 8.0 m. The average value of the vehicle's skid resistance (friction coefficient) is (A) 0.64 (B) 6.25 (C) 0.16 (D) None of these

Description : In a braking test, a vehicle travelling at 36 km ph was stopped at a braking distance of 8.0 m. The average value of the vehicle's skid resistance (friction coefficient) is (A) 0.64 (B) 6.25 (C) 0.16 (D) None of these

Last Answer : Answer: Option C

Differential lock in tractor is used to improve a) Lateral stability b) Braking performance c) Hydraulic lift d) Traction of a wheel

Description : Differential lock in tractor is used to improve a) Lateral stability b) Braking performance c) Hydraulic lift d) Traction of a wheel

Last Answer : Braking performance 

Differential lock in tractor is used to improve a) Lateral stability b) Braking performance c) Hydraulic lift d) Traction of a wheel

Description : Differential lock in tractor is used to improve a) Lateral stability b) Braking performance c) Hydraulic lift d) Traction of a wheel

Last Answer : ans d

------------- is a feature that alerts a driver to an imminent crash and helps them use the maximum braking capacity of the car. a) AEB b) Air Bag c) Vehicles d) Electronic Stability control

Description : ------------- is a feature that alerts a driver to an imminent crash and helps them use the maximum braking capacity of the car. a) AEB b) Air Bag c) Vehicles d) Electronic Stability control

Last Answer : a) AEB

Electronic Stability Program is use to a) Assist in braking b) Reducing loss of traction c) Use in ECU d) for proper loading and unloading of weight in vehicle

Description : Electronic Stability Program is use to a) Assist in braking b) Reducing loss of traction c) Use in ECU d) for proper loading and unloading of weight in vehicle

Last Answer : b) Reducing loss of traction

In India, Autonomous Emergency Braking system (AEB) could become mandatory on new cars by________ a) 2020 b) 2024 c) 2022 d) 2026

Description : In India, Autonomous Emergency Braking system (AEB) could become mandatory on new cars by________ a) 2020 b) 2024 c) 2022 d) 2026

Last Answer : c) 2022

What’s the primary advantage of a anti- lock braking system a) They allow you to stop easier b) They prevent locking c) They allow you to steer while braking

Description : What’s the primary advantage of a anti- lock braking system a) They allow you to stop easier b) They prevent locking c) They allow you to steer while braking

Last Answer : c) They allow you to steer while braking

Which of these is the purpose of the power-split device? • To split electrical energy into mechanical energy • To allow both the engine and electric motor to propel the vehicle • To recharge the battery while braking

Description : Which of these is the purpose of the power-split device? • To split electrical energy into mechanical energy • To allow both the engine and electric motor to propel the vehicle • To recharge the battery while braking

Last Answer : • To allow both the engine and electric motor to propel the vehicle

Which of these is the purpose of power-split device a) To split Electrical Energy into Mechanical Energy. b) To allow both the engine and Electric motor to propel the vehicle c) To recharge the battery while braking d) To recharge the brakes while driving

Description : Which of these is the purpose of power-split device a) To split Electrical Energy into Mechanical Energy. b) To allow both the engine and Electric motor to propel the vehicle c) To recharge the battery while braking d) To recharge the brakes while driving

Last Answer : b) To allow both the engine and Electric motor to propel the vehicle

_____ technology helps to stop a combustion engine when the vehicle pulls to a stop and restart it when driver accelerates. • Start stop technology • Passive braking technology • Regenerative braking technology • Internal cooling technology

Description : _____ technology helps to stop a combustion engine when the vehicle pulls to a stop and restart it when driver accelerates. • Start stop technology • Passive braking technology • Regenerative braking technology • Internal cooling technology

Last Answer : • Regenerative braking technology

Regenerative braking involves : a) Nano fibers that repair the surface of brake pads b) Reducing the amount of friction c) Reclaiming heat from the brake and using it for power d) All of the above

Description : Regenerative braking involves : a) Nano fibers that repair the surface of brake pads b) Reducing the amount of friction c) Reclaiming heat from the brake and using it for power d) All of the above

Last Answer : c) Reclaiming heat from the brake and using it for power

Hybrid vehicles convert energy that is normally lost through braking into electrical energy. What is the term that is used for this recycling of energy? APerpetual motion BRegenerative breaking C. Kinetic conversation D. Hybrid archamy

Description : Hybrid vehicles convert energy that is normally lost through braking into electrical energy. What is the term that is used for this recycling of energy? APerpetual motion BRegenerative breaking C. Kinetic conversation D. Hybrid archamy

Last Answer : BRegenerative breaking

Consider the following salient points in a stress-strain curve of a mild steel bar: 1. Yield point 2. Braking point 3. Yield plateau 4 . Proportionality limit 5. Ultimate point The correct sequence in which they occur while testing the mild steel bar in tension from initial zero strain to failure is (a) 4, 1, 2, 3 and 5 (b) 1, 4, 3, 5 and 2 (c) 4, 1, 3, 5 and 2 (d) 1, 4, 2, 3 and 5

Description : Consider the following salient points in a stress-strain curve of a mild steel bar: 1. Yield point 2. Braking point 3. Yield plateau 4 . Proportionality limit 5. Ultimate point The correct sequence in which they occur while testing the mild ... , 5 and 2 (c) 4, 1, 3, 5 and 2 (d) 1, 4, 2, 3 and 5

Last Answer : (c) 4, 1, 3, 5 and 2

The phrase “BRAKING CO-EFFICIENT 20” from ATC means that the braking action is:

Description : The phrase “BRAKING CO-EFFICIENT 20” from ATC means that the braking action is:

Last Answer : poor

An example of a general call is: a. STOP IMMEDIATELY I SAY AGAIN STOP IMMEDAITELY b. BRAKING ACTION UNRELIABLE c. ALL STATIONS

Description : An example of a general call is: a. STOP IMMEDIATELY I SAY AGAIN STOP IMMEDAITELY b. BRAKING ACTION UNRELIABLE c. ALL STATIONS

Last Answer : c. ALL STATIONS