Question

A dc series motor is connected to a constant-toque load, which may be considered to require...

A dc series motor is connected to a constant-toque load, which may be considered to require a constant electromagnetic torque regardless of motor speed. Neglect the voltage drops due to the armature and series-field resistances, the armature reaction, and the effects of saturation.

(a) By what percent is the motor speed changed wgen the line voltage is reduced from 230 V to 200 V?

(b) Repeat (a), assuming a shunt motor.

(c) State briefly what effects saturation might have on the answers to (a) and (b).

Engineering   Electrical-Engineering   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A 230 V, 250 rpm, 100 A separately excited dc motor has an armature resistance of...
A 230 V, 250 rpm, 100 A separately excited dc motor has an armature resistance of 0.5 Ω. The motor is connected to 230 V dc supply and rated dc voltage is applied the field winding. It is driving a load whose torque-speed characteristic is given by TL = 500 − 10ω where ω is the speed in rad/sec and TL is the load torque in N-m. Find (a) the steady state speed at which the motor will drive the...
The full-load armature current of a 5 hp, 150 V shunt dc motor is 30 A....
The full-load armature current of a 5 hp, 150 V shunt dc motor is 30 A. The field (shunt) resistance and the armature resistance of the motor are ????F = 125 ? and ???????? = 0.15, respectively. At a random speed of 1800 rpm magnetization curve of the motor has measured and is shown in the table below. ????0 (V) armature voltage 10 90 110 140 170 185 ???????? (A) field (shunt) current 0 0.82 1 1.2 1.7 2.88 Calculate...
Question 2 The full-load armature current of a 5 hp, 150 V shunt dc motor is...
Question 2 The full-load armature current of a 5 hp, 150 V shunt dc motor is 30 A. The field (shunt) resistance and the armature resistance of the motor are ????F=125 ? and ????????=0.15, respectively. At a random speed of 1800 rpm magnetization curve of the motor has measured and is shown in the table below. EO(V) armature voltage 10 90 110 140 170 185 IF (A) field (shunt) current 0 0.82 1 1.2 1.7 2.88 Calculate the following: a....
A 200 V DC, 1,800 RPM shunt connected motor has an armature resistance of 0.4 ohm...
A 200 V DC, 1,800 RPM shunt connected motor has an armature resistance of 0.4 ohm and a brush resistance of 0.4 ohm; brush voltage drop of 6.0 V, independent of load. The resistance of the shunt field is 230 ohm. The full load rated line current is 40 A. When the motor is operated at no load the line current is 5 A and the speed is 1750 RPM. Calculate speed at rated load Calculate speed at .3 rated...
A 25-hp, 240V, DC shunt motor has armature and field resistances of 0.2 ? and 120...
A 25-hp, 240V, DC shunt motor has armature and field resistances of 0.2 ? and 120 ?, respectively. At no load and rated voltage, the motor draws a line current of 5A and its speed is 1250 rpm. When driving a certain load, the input to the motor is 15KW. For this condition, find: a.The speed of the motor b.The developed torque The efficiency of the motor at this load
A separately excited DC motor has the following parameters: field resistance = 250 ?, armature resistance...
A separately excited DC motor has the following parameters: field resistance = 250 ?, armature resistance = 0.03 ?, terminal voltage = 250 V and field voltage = 250 V. Initially the machine runs at 1000 rpm with the terminal voltage = 250 V and armature current = 120 A. a) find the speed of the motor if the load torque dropped to 50% of its original value, b) find the speed of the motor if the armature voltage is...
a)Explain the shunt excitation and compound excitation of DC generator. b)A 240V compound DC motor has...
a)Explain the shunt excitation and compound excitation of DC generator. b)A 240V compound DC motor has the armature, series field and shunt field resistances are 0.22 Ω, 0.04 Ω and 200 Ω respectively. On full load, the line current is 17.5 A and the motor runs at 1800 rpm. (short shunt) i) Draw the diagram and the power flow of the motor. ii) Find the back EMF of the motor. iii) Find the mechanical power developed. iv) Find the output...
A 230-V DC shunt motor has armature circuit resistance of 0.25 ? and field circuit resistance...
A 230-V DC shunt motor has armature circuit resistance of 0.25 ? and field circuit resistance of 115 ?. At full load armature draws a current of 38 A and the speed is measured at 1050 rpm. Find the developed torque. The field rheostat is now changed so that total field resistance is 144 ?. Find the speed under this condition. Assume that the armature current does not change. Assuming the rotational losses amount to 600 W, find the efficiency...
A separate excited DC motor is running at 1000 rpm when the armature voltage is 600...
A separate excited DC motor is running at 1000 rpm when the armature voltage is 600 V. The motor has a field constant Kphi = 4 V.sec and the armature resistance of the motor is 0.8 Ohms. i. Calculate the value of the resistance of the dynamic braking at full load. The armature current should be limited to 200 % of the rated value. ii. If the motor operates in regenerative braking at a speed of 1200 rpm, calculate the...
Q3: (a) Determine the terminal voltage of a dc shunt generator which develops an e.m.f. of...
Q3: (a) Determine the terminal voltage of a dc shunt generator which develops an e.m.f. of 240V and has an armature current of 50 A on load. Assume the armature resistance is 0.04Ω. [3 marks] (b) A lap wound armature is used in a 4-pole dc machine and 70 coils on the armature each containing 10 turns. The flux per pole in the machine is 40 mWb and the machine rotates at 500 rpm; (a) How many current paths are...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT