24. DC motor requires 90 V and 3.0 A of current in order to function properly....
A 120-V, series-wound motor has a field resistance of 4.0 and an armature resistance of 2.5 . (a) Determine the current drawn by the motor at the very instant it is switched on, i.e., when it has not started to rotate. (b) When it is operating at nominal speed, a back emf of 85.0 V is generated. How much current is drawn in this case? (c) What is the furnished mechanical power? (d) How much power is dissipated?...
Q1b) DC Machines [ 6 marks ] You are given a 24 V DC motor. When you connect it to a 24 V supply, under no-load conditions it spins at 2,000 rpm. With the same 24 V supply, when the motor is stalled, the input current is 50 A. i) Calculate the back-emf constant and hence the stall torque of the motor. Find also the armature resistance. [3 marks ] ii) The DC motor has a rated input current of...
QUESTION 3 and the lifting speed As the resistance before the motor decreased the motor voltage QUESTION 4 Consider a circuit with a resistor in series with a motor, like observed in Activity 2 of the Week 10 Practical, when the load on the motor increases the voltage across the motor and the current through the motor Under this higher load the lifting speed and the motor torque QUESTION5 If the power supply is set to 5 V and a...
QUESTION 3 and the lifting speed As the resistance before the motor decreased the motor voltage QUESTION 4 Consider a circuit with a resistor in series with a motor, like observed in Activity 2 of the Week 10 Practical, when the load on the motor increases the voltage across the motor and the current through the motor Under this higher load the lifting speed and the motor torque QUESTION5 If the power supply is set to 5 V and a...
1. A 300 V compound motor has armature resistance 0.18 Ω, series field resistance 0.3 Ω and shunt field resistance 100 Ω. The rotational losses are 200 W. On full load the line current is 25 A and the motor runs at 1800 rpm. Determine: (i) the developed mechanical power (ii) the output power (iii) the output torque (iv) the efficiency at full load 2. A 120 V series motor has 0.2 Ω field resistance. On full load, the line...
A DC motor, when supplied from a 90 V power supply is observed to rotate under no-load conditions at 1,200 rpm. A stall test shows that the winding resistance is 2 Ω. Assume a linear model for the DC machine as presented in lectures. What is the back-emf constant for this machine? Give your answer in V.s.rad-1 to 3 decimal places.
An RLC circuit consists of an alternating voltage source with RMS voltage 90 V and frequency 100 Hz, 180 ohm resistor, 200mH inductor, and a 900 micro-F capacitor, all wired in series. A) What is inductive reactance of the circuit? B) What is the capacitive reactance of the circuit?C) What is the impedance of the circuit? D)What is RMS current in the circuit?E) If the frequency is adjustable what frequency should you use to maximize the current in the circuit?
A separately excited dc motor is fed by a 3-phase, 6-pulse converter shown in figure Q5. The 3-phase line is a 500 V, 60 Hz supply. At rated condition, the dc motor armature current is 15 A. The dc motor armature resistance is 0.15 Ω and the rated speed is 1700 rpm. If the delay angle of the converter is 36 °, calculate the following: 3-phase (2 0 line Figure Q5. (2 marks) Rated voltage of the motor a. b....
FQ3
3. A 240 V DC series motor with 0.1 ohm armature resistance and 0.1 ohm field resistance runs at 1200 rpm and 100 Amp. of full load speed and armature current respectively. The motor has a brush contact drop of 2 volts. Find the motor full load torque and efficiency If the motor is to drive a pump that requires a torque of 150 NM, find the speed as the motor drives the given pump. a. b.
A 6 hp, 180 V shunt dc motor draws a full-load current of 30 A from the power supply. The motor has a field (shunt) resistance of 150 Ω. The armature resistance of the motor is 0.1 Ω. When the motor speed is 1800 rpm (this is not the full-load speed), the relationship between the induced voltage