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A straight wire having mass of 1.2 kg and length of 1m carries a current of 5 A. If the wire is suspended in mid-air by a uniform horizontal magnetic field, then the magnitude of field isA. 0.65TB. 1.53TC. 2.4TD. 3.2T |
Answer» Correct Answer - C For mid-air suspension the upward force F on wire due to magnetic field B must be balanced by the force due to gravity, then `IlB=mg, B=(mg)/(Il)` Here, `m=1.2kg, g = "10 m s"^(-2), I= 5A, l=1m` `B=(1.2xx10)/(5xx1)=2.4T` |
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