Page 81 - Basic Electrical Engineering
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Figure 1.17 Magnetic field energy
Example 1.12 A conductor of length 0.5 m is placed in a magnetic field of
2
strength 0.5 Wb/m . Calculate the force experienced by the conductor when a
current of 50 A flows through it. If the force moves the conductor at a
velocity of 20 m/sec, calculate the EMF induced in it.
Solution:
Force, F on a current-carrying conductor placed in a magnetic field is given
as
F = B I ℓ Newton
Substituting the values,
2
F = 0.5 Wb/m × 50 × 0.5 m
= 12.5 N
Induced EMF, e in a conductor moving in a magnetic field is given as
e = B l v V
Substituting the given values,
2
e = 0.5 Wb/m × 0.5 m × 20 m/sec
= 5 Wb/sec = 5 V
