Consider a separately-excited DC motor with an armature resistance RA-0.08 2 and terminal voltage VT- 115 V. The motor rated speed is 1800 RPM. The field winding supply Vr- 24 V and the total field resistance 480 Assume No armature reaction in this machine. The variation of the armature terminal voltage as a function of the field current is measured under no-load conditions and shown below: IF (A) EA (V) 0.0 0.1 0.3 S5 102 These values were taken at speed n- 1800 RPNI 0.2 60 0.4 0,5 0.6 0.7 0.8 0.9 140 1.0 30 115 125 132 137 141 If the motor is driving a load at an armature current La 60 A. its rotational speed is 1587 RPM, with rotational losses of 700 Watt. Find the efficiency of this motor. Select one: a. None b. 9% Efficiency = 74.5 % C. 96 Efficiency- 85.5% d. 95 Efficiency-91.2 % 4) A ENG SW

Consider a separately-excited DC motor with an armature resistance RA-0.08 2 and terminal voltage VT- 115 V. The motor rated speed is 1800 RPM. The field winding supply Vr- 24 V and the total field resistance 480 Assume No armature reaction in this machine. The variation of the armature terminal voltage as a function of the field current is measured under no-load conditions and shown below: IF (A) EA (V) 0.0 0.1 0.3 S5 102 These values were taken at speed n- 1800 RPNI 0.2 60 0.4 0,5 0.6 0.7 0.8 0.9 140 1.0 30 115 125 132 137 141 If the motor is driving a load at an armature current La 60 A. its rotational speed is 1587 RPM, with rotational losses of 700 Watt. Find the efficiency of this motor. Select one: a. None b. 9% Efficiency = 74.5 % C. 96 Efficiency- 85.5% d. 95 Efficiency-91.2 % 4) A ENG SW

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

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