JEE Advanced2012PhysicsElectromagnetic InductionActual
A current carrying infinitely long wire is kept along the diameter of a circular wire loop, without touching it, the correct statement(s) is(are)
Options
- AThe emf induced in the loop is zero if the current is constant.
- BThe emf induced in the loop is finite if the current is constant.
- CThe emf induced in the loop is zero if the current decreases at a steady rate.
- DThe emf induced in the loop is infinite if the current decreases at a steady rate.
Correct answer
A. The emf induced in the loop is zero if the current is constant.
Step-by-step solution
If the current is constant, the emf induced in the loop zero. Emf will be induced in the circular wire loop when flux through it changes with time. e =- t when the current is constant, the flux changing through it will be zero. Also, if the current decreases at steady rate, the emf. induced in the loop is zero. When the current is decreasing at a steady rate then the change in the flux (decreasing inwards) on the right half of the wire is equal to the change in flux (decreasing outwards) on the left half of the wir