1)

 A horizontal rod of mass 0.01 kg and length 10 cm is placed on a friction less plane inclined at an angle 60° with trhe horizontal and with the  length  of rod parallel to the edge of the inclined  plane. A uniform magnetic  fiewld is applied 'Vertically downwards. If the current through the rod  is 1.73 A, then the value of magnetic field induction B  for which  the rod remains stationary  on the inclined  plane is 


A) 1 T

B) 3 T

C) 2.5

D) 4 T

Answer:

Option A

Explanation:

 Here two forces acting on the rod simultaneously

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 From FBD, mg sing 60 = Bil cos 60°

 $B=\frac{mg}{il}\tan 60^{0}=\frac{0.01\times10}{173\times0.1}\times\sqrt{3}=1T$