DC motor gross torque example

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DC motor gross torque example

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Description : Why a dc series motor has a high starting torque?

Last Answer : motor

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Last Answer : The armature torque of the D.C. shunt motor is proportional to armature current.

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Description : In a double squirrel cage induction motor, good starting torque is produced as (A) Large current flows through the outer high resistance winding. (B) Large current flows through the inner high ... the outer high resistance winding. (D) Large current flows through the inner low resistance winding.

Last Answer : In a double squirrel cage induction motor, good starting torque is produced as Large current flows through the outer high resistance winding.

Description : Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be

Last Answer : Torque developed by a three-phase, 400V, induction motor is 100 N -m. If the applied voltage is reduced to 200-V, the d'veloped torque will be 25 N -m

Description : The torque developed by any 3-phase induction motor at 0.8 p.u. slip is (A) Full-load torque (B) unstable torque (C) starting torque (D) break down

Last Answer : The torque developed by any 3-phase induction motor at 0.8 p.u. slip is unstable torque

Last Answer : For the same H.P. rating and full load speed, following motor has poor starting torque differentially compounded.

Last Answer : Speed torque characteristic of a repulsion induction motor is similar to that of a D.C. compound motor.

Last Answer : In repulsion motor, maximum torque is developed when brush axis is at 45° electrical to the field axis.

Last Answer : A synchronous motor can develop synchronous torque at synchronous speed.

Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?

Last Answer : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.

Description : What is the maximum value of torque angle in synchronous motor?

Last Answer : The maximum value of torque angle in synchronous motor is 90 degrees electrical.

Last Answer : Capacitor start motor has high torque in starting

Description : 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 :

Last Answer : 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 : 0.075

Description : Gross errors occur in measurements because of (A) disturbances about which we are unaware. (B) human mistakes. (C) inherent shortcomings in the instrument. (D) loading effects on the meters.

Last Answer : Gross errors occur in measurements because of human mistakes.

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

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Description : State at least one function and the material used for the following parts of DC Motor.

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Last Answer : increases

Description : What would happen if a DC motor was supplied with AC ?

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Description : State the function of following parts of DC motor : i) Yoke ii) Poles iii) Field winding iv) Commutator. 

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Last Answer : Because if the load is increasing then the torque must also be increase. If not then the speed of motor will decrease.

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

Last Answer : Electric trains require an inverse torque speed characteristics for proper operation. That is a higher torque is required at start (when speed is nil or low) and as the train picks up ... torque - speed characteristics of DC series motors match, these motors are suitable for electric trains

Description : 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

Last Answer : 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 474 V

Description : 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

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Description : 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) ... in first & second quadrants (C) can be operated in first & fourth quadrants (D) cannot be operated

Last Answer : 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 : can be operated in first & fourth quadrants

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Last Answer : The function of a brush and commutator arrangement in a dc motor is to produce unidirectional torque

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Last Answer : In a DC motor, it is important to place the brushes along Magnetic Neutral Axis

Description : 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) ... proportional to α and inversely proportional to Φ (D) directly proportional to Φ and inversely proportional to α

Last Answer : 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 directly proportional to α and inversely proportional to Φ

Description : 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)

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Last Answer : principle

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Description : Chopper controlled DC motor

Last Answer : Chopper controlled DC motor

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Last Answer : Armature control of DC motor

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Last Answer : Field control of DC motor

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Last Answer : Separately Excited DC motor

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Last Answer : The shaft torque of a d.c. motor is less than its armature torque because of rotational losses.

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

Last Answer : The Eb/V ratio of a d.c. motor is an indication of its efficiency.