Q2 A DC shunt motor is connected to a 220 V supply. Figurel below shows the time/current characteristics with a resistance starter. If armature resistance is 0.120, a) What is the maximum current that is flowing in the armature at the instant of starting? b) What is the minimum current in the armature? c) How many sections does this starter resistance have? Show your work. d) Calculate the required starter resistance required to limit the current to the maximum value. 270 162 12

Q2 A DC shunt motor is connected to a 220 V supply. Figurel below shows the time/current characteristics with a resistance starter. If armature resistance is 0.120, a) What is the maximum current that is flowing in the armature at the instant of starting? b) What is the minimum current in the armature? c) How many sections does this starter resistance have? Show your work. d) Calculate the required starter resistance required to limit the current to the maximum value. 270 162 12

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter5: Resistors

Section: Chapter Questions

Problem 1PA

See similar textbooks

Similar questions

Q2 A DC shunt motor is connected to a 220 V supply. Figurel below shows the time/current characteristics with a resistance starter. If armature resistance is 0.12 0, a) What is the maximum current that is flowing in the armature at the instant of starting? b) What is the minimum current in the armature? c) How many sections does this starter resistance have? Show your work. d) Calculate the required starter resistance required to limit the current to the maximum value. 270 162 13 t.
Reducing the supply voltage so that Vnew = Vold / V3 reduces the maximum torque of the motor so that Tmaxnew= ...Tmaxold . * .... ...
Answer please in 10 minutes
4. A shunt motor designed to operate at 115 V, has an armature resistance is 0.12 ohms and the motor is taking 60 A in armature current at full load. Determine the value of the external resistance to be inserted in the armature circuit so that the armature current shall not exceed twice its full load value at starting. A. 0.838 ohm C. 0.667 ohm B. 0.919 ohm D. 0.733 ohm
A 250 V d.c. shunt motor takes a current of 20 A. Resistance of shunt field winding is 200 ohm and the armature is 0.3 ohm. What is the current in the armature ?
A 220 V DC series motor runs drawing a current of 30 A from the supply. Armature and field circuit resistances are 0.4 and 0.1 respectively. The load torque varies as the square of the speed. The flux in the motor may be taken as being proportional to the armature current. To reduce the speed of the motor by 50% the resistance in ohms that should be added in series with the armature is
A shunt-wound DC motor with the field coils and rotor connected in parallel (Figure 1) operates from a 130 V DC power line. The resistance of the field windings, R. is 208 n. The resistance of the rotor, R,, is 4.90 1. When the motor is running, the rotor develops an emf E. The motor draws a current of 4.46 A from the line. Friction losses amount to 45.0 W Part C Compute the emf E. • View Available Hint(s) Tematates Symbols undo redo Tese keyboard shortcuts Help V Submit Part D Compute the rate of development of thermal energy in the field windings. Express your answer in watts. > View Available Hint(s) Templates Symbols undo redo Teset keyboard shortcuts Help Pan,windings = Figure W K 1 of 1 Submit Part E Compute the rate Pin.rotor of development of thermal energy in the rotor. R ER, Express your answer in watts. > View Available Hint(s) Templates Symbols undo redo teset keyboard shortcuts help Pinrotor=
The armature resistance of a 250 V D.C. shunt motor is 0.5 Ω. The minimum and maximum current during starting are 50.25 A and 67 A respectively. Determine the number of sections of the starter and resistance of each section..
ASAP. PLEASE ANSWER THE QUESTIONS TO GET A LIKE a.In a dc shunt motor, the shunt field resistance is 100 ohms and the armature resistance is 0.01 ohm. It is supplied by a 250V source. If the shunt field is disconnected and is connected to a rheostat to control the speed of the dc machine, what should be the case if it is desired to increase the speed of the motor? -The resistance of the field rheostat should be decreased to be able to increase the speed of the motor -The resistance of the field rheostat should be increased to be able to increase the speed of the motor -The resistance of the field rheostat should not be changed to be able to increase the speed of the motor -The terminals of the field rheostat should be short circuited to be able to increase the speed of the motor b. In a dc shunt machine, reversing the terminals of the brushes will make the rotation of the shaft to rotate in other direction (e.g. from clockwise to counter-clockwise). Is it TRUE OR…
Does a DC motor have to be turning in order for it to develop torque? a) yes b) no Most DC motor consist of many turns per armature loop as well as many evenly distributed loops per al mature. a) true b) false Brushes a DC motor. a) are part of the electrical circuit in b) provide a sliding electrical contact to the commutator of c) are made of a material which is softer than the commutator segments of d) all of the above
A series motor runs at 700 rev/min when the voltage is 300 V and the current is 20 A. The armature resistance is 0.3 2 and the series field resistance is 0.1 2. Determine the resistance to be connected in series to reduce the speed to 500 rev/min with the same current
ASAP ASAP ASAP previous answer is wrong