MHT CET202124 Sep 2021Morning ShiftPhysicsMagnetic Effects of CurrentActual
A long solenoid carrying current I ₁ produces magnetic field B ₁ along its axis. If the current is reduced to 20 % and number of turns per cm are increased five times, then new magnetic field B ₂ is equal to
Options
- AB ₁
- BB ₁ 5
- C5 ~B ₁
- D0.25 ~B ₁
Correct answer
A. B ₁
Step-by-step solution
aligned & B ₁= ₀ n ₁ I ₁ and B ₂= ₀ n ₂ I ₂ & n ₂=5 n ₁ I ₂=0.2 I ₁ & B ₂ ~B ₁ = n ₂ n ₁ I ₂ I ₁ =5 0.2=1 & B ₂= B ₁ aligned