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alamin
Jan18-06, 02:56 AM
The magnetic field in the electric motor of a toy train is provided by a permanent magnet. The motor works from a 12 V DC supply and its armature has a resistance of 5.0 ohms. Running a light load on a level track, it reaches a speed of 0.45 m/s and takes 0.6 A. When a carriage is hitched up to the engine the maximum speed reached is 0.3 m/s.
a. What current does the motor take?
b. What maximum current would the motor take if started from rest?