Solved papers for JEE Main & Advanced JEE Main Solved Paper-2015

done JEE Main Solved Paper-2015 Total Questions - 3

• question_answer1) 4 Two long current carrying thin wires, both with current I, and held by insulating threads of length L and are in equilibrium as shown in the figure, with threads making an angle \['\theta '\] with the vertical. If wires have mass \[\lambda \]per unit length then the value of I is : (g = gravitational acceleration) [JEE Main Solved Paper-2015 ]
  A)
  \[2\sqrt{\frac{\pi gL}{{{\mu }_{0}}}\tan \theta }\]            
  done clear
  B)
  \[\sqrt{\frac{\pi \lambda gL}{{{\mu }_{0}}}\tan \theta }\]
  done clear
  C)
  \[\sin \theta \sqrt{\frac{\pi \lambda gL}{{{\mu }_{0}}\cos \theta }}\]      
  done clear
  D)
  \[2\sin \theta \sqrt{\frac{\pi \lambda gL}{{{\mu }_{0}}\cos \theta }}\]
  done clear
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• question_answer2) A rectangular loop of sides 10 cm and 5 cm carrying a current I of 12A is placed in different orientations as shown in the figures below : [JEE Main Solved Paper-2015 ]

  A
  B
  C
  D

  If there is a uniform magnetic field of 0.3 T in the positive z direction, in which orientations the loop would be in (i) stable equilibrium and (ii) unstable eqilibrium?
  A)
  (b) and (d), respectively
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  B)
  (b) and (c), respectively
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  C)
   (a) and (b) , respectively
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  D)
  (a) and (c), respectively
  done clear
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• question_answer3) Two coaxial solenoids of different radii carry current I in the same direction. Let \[{{\vec{F}}_{1}}\]be the magnetic force on the inner soleoid due to the outer one and \[{{\vec{F}}_{2}}\]be the magnetic force on the outer solenoid due to the inner one. Then : [JEE Main Solved Paper-2015 ]
  A)
  \[{{\vec{F}}_{1}}\]is radially inwards and \[{{\vec{F}}_{2}}=0\]
  done clear
  B)
  \[{{\vec{F}}_{1}}\]is radially outwards and \[{{\vec{F}}_{2}}=0\]
  done clear
  C)
   \[{{\vec{F}}_{1}}={{\vec{F}}_{2}}=0\]
  done clear
  D)
  \[{{\vec{F}}_{1}}\]is radially inwards and \[{{\vec{F}}_{2}}\]is radially onwards
  done clear
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