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? (e) What is the power furnished by the source? (f) Suppose now the load on the motor has increased so that it draws a 16.0-A current, what is the back emf of the motor in this case.
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A 120-V, series-wound motor has a field resistance of 4.0 and an armature resistance of...
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...
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In a shunt-wound dc motor with the field coils and rotor
connected in parallel (see the figure (Figure 1)), the resistance
Rf of the field coils is Rf = 103 Ω and the resistance Rr of the
rotor is Rr = 5.5 Ω. When a potential difference of V = 120 V is
applied to the brushes and the motor is running at full speed
delivering mechanical power, the current supplied to it is 4.90
A.
Part A.) What is...
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