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NEET-XII-Physics

38: Electromagnetic Induction

with Solutions - page 5
Qstn# iv-6-a Prvs-QstnNext-Qstn
  • #6-a
    its removal, (b) its restoration and (c) its motion.
    Ans : When the coil is removed from the magnetic field:
    Initial magnetic flux through the coil, Ï•1 = BA
    ∴ ϕ1 = 50 × 0.5 × 0.5 T-m2
    = 12.5 T-m2
    Now,
    Initial magnetic flux through the coil, Ï•2 = 0
    Time taken, t = 0.25 s
    The average emf induced is given by
    `` e=-\frac{∆\,\mathrm{\,\varphi \,}}{∆t}=\frac{{\,\mathrm{\,\varphi \,}}_{1}-{\,\mathrm{\,\varphi \,}}_{2}}{dt}``
    `` =\frac{12.5-0}{0.25}=\frac{125\times {10}^{-1}}{25\times {10}^{-2}}=50\,\mathrm{\,V\,}`` (b) When the coil is taken back to its original position:
    Initial magnetic flux through the coil, Ï•1 = 0
    Initial magnetic flux through the coil, Ï•2 = 12.5 T-m2
    Time taken, t = 0.25 s
    The average emf induced is given by
    `` e=\frac{12.5-0}{0.25}=50\,\mathrm{\,V\,}`` (c) When the coil is moving outside the magnetic field:
    Initial magnetic flux, Ï•1 = 0
    Final magnetic flux, Ï•2 = 0
    Because there is no change in the magnetic flux, no emf is induced.
    Page No 306:
  • #6-b
    its restoration and
    Ans : When the coil is taken back to its original position:
    Initial magnetic flux through the coil, Ï•1 = 0
    Initial magnetic flux through the coil, Ï•2 = 12.5 T-m2
    Time taken, t = 0.25 s
    The average emf induced is given by
    `` e=\frac{12.5-0}{0.25}=50\,\mathrm{\,V\,}``
  • #6-c
    its motion.
    Ans : When the coil is moving outside the magnetic field:
    Initial magnetic flux, Ï•1 = 0
    Final magnetic flux, Ï•2 = 0
    Because there is no change in the magnetic flux, no emf is induced.
    Page No 306: