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Moving Charges and Magnetism — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsMoving Charges and Magnetism3 Marks
Question
A straight wire of length l can slide on two parallel plastic rails kept in a horizontal plane with a separation d. The coefficient of friction between the wire and the rails is $\mu.$ If the wire carries a current i, what minimum magnetic field should exist in the space in order to slide the wire on the rails?
✓

Answer


Mass = m
length = l
Current = i
Magnetic field = B = ?
$\text{iBl}=\mu\text{mg}$
$\Rightarrow\text{B}=\frac{\mu\text{gm}}{\text{il}}$

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