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Question
Consider a 10-cm long portion of a straight wire carrying a current of 10 A placed in a magnetic field of 0.1 T making an angle of 53° with the wire. What magnetic force does the wire experience?
Solution
Given:
A straight wire of length, l = 10 cm
Electric current flowing through the wire, I = 10 A
Magnetic field, B = 0.1 T
Angle between the wire and magnetic field, θ = 53˚
Magnetic force,
`vecF = I vecl xx vecB`
∴ `|vecF| =llBsintheta`
∴ `|vecF| = llBsin53°`
⇒ F = 10 × 10 × 10^-2 ×0.1 ×0.798
`⇒ vecF = 0.07989 ≈0.08 N`
The direction of force can be found using Fleming's left-hand rule.
Therefore, the direction of magnetic force is perpendicular to the wire as well as the magnetic field.
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