# Chopper controlled DC motor

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Chopper controlled DC motor

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Chopper controlled DC motor

## Related questions

A dc chopper is fed from a constant voltage mains the duty ratio of chopper is progressively increased while the chopper feeds an RL load. The per unit current ripple would  (1) increase progressively  (2) decrease progressively  (3) decrease to a minimum value at α = 0.5 and then increase  (4) increase to a maximum value at α = 0.5 and then decrease

A 3 -phase, fully controlled, converter is feeding power into a DC load at a constant current of 150 A, the rms value of the current flowing through each thyristor of the converter is

The no-load speed of a single-phase SCR bridge converter fed separately excited dc motor operating at a firing delay angle, α and flux, Φ (A) directly proportional to α and Φ (B) inversely proportional to α and Φ (C) directly proportional to α and inversely proportional to Φ (D) directly proportional to Φ and inversely proportional to α

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

The speed of a D.C. motor can be controlled by varying  1. Its flux per pole 2. Resistance of armature circuit 3. Applied voltage 4. All of the above

Why does the speed of a DC shunt motor decrease as the load increases?

Describe the reason of using dc series motor for electric trains.

A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The net Voltage across armature resistance at the time of plugging will be

A 200 V dc shunt motor is running at 1000 rpm and drawing a current of 10 A. Its armature winding resistance is 2 Ohm. It. is braked by plugging. The resistance to be connected in series with armature to restrict armature current to 10 A, is

A separately excited dc motor operating in first quadrant is fed from 3-phase semi -converter free -wheeling diode is open circuited, then the motor :  (A) can be operated in first quadrant (B) can be operated in first & second quadrants (C) can be operated in first & fourth quadrants (D) cannot be operated

In a 2 kW, 200 V, 1000 rpm. DC series motor the torque at full load was found to be 0.3 N -m. The torque at half full load in N -m is :

The function of a brush and commutator arrangement in a dc motor is to  (1) produce unidirectional torque (2) produce unidirectional current in the armature (3) help in changing the direction of rotation of the armature (4) reduce sparking

In a DC motor, it is important to place the brushes along ______ A) Magnetic Neutral Axis B) Normal Geometric Axis C) Nominal Geometric Axis D) None of these

In a 4-pole wave winding connected dc motor, the cross-magnetizing AT/pole for a brush shift of θ radians (A) Armature amp-conductors × (θ/360o) (B) Armature amp-turns × (θ/360o) (C) Armature amp-conductors × (1/4 - θ/360o) (D) Armature amp-conductors × (1/8 - θ/360o)

In DC motor iron losses are occurred in?

Which type of starter is used to start the DC motor?

What are the advantages of DC series motor?

Why dc series motor should not be started at no load?

Why a dc series motor has a high starting torque?

What is the RPM of a DC motor?

What is the principle of DC motor?

What is the back EMF of a dc motor?

Why DC motor is used for traction?

What are the speed control methods of dc motor?

Armature control of DC motor

Field control of DC motor

Separately Excited DC motor

Four Quadrant Operation Of DC Motor

An FET is a better chopper than a BJT because it has (A) lower offset voltage (B) higher series ON resistance (C) lower input current (D) higher input impedance

In a thyristor D.C. chopper, which type of commutation results in best performance ?

A 230 V, 50 Hz phase controlled single-phase full-controlled SCR bridge converter draws 15 A constant dc current. If the source inductance is 3 mH, the drop in dc output voltage is (A) 4.5 V (B) 6.75 V (C) 9 V (D) 13.5 V

A step-down chopper, fed from a 120 volt DC source, operates a DC motor whose armature e.m.f. and armature resistance are 100 volt and 0.5Ω respectively. With the magnitude control ratio 0.6, the quadrant of operation DC motor is  (a) First (b) Second (c) Third (d) Fourth

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% the power return to the DC supply is  (a) 78 kW (b) 58 kW (c) 38 kW (d) 48 kW

A d.c. motor can be looked upon as d.c. generator with the power flow?

The Eb/V ratio of a d.c. motor is an indication of its?

The normal value of the armature resistance of a d.c. motor is?

The counter e.m.f. of a d.c. motor?

In a d.c. motor, unidirectional torque is produced with the help of