TS EAMCET 4-Aug-2021 Shift 2 Question Paper

Given, initial and final number of turns per unit length be ni and nf. i.e. nf=2ni and Bi,Bf are the initial and final magnetic field
As we know that, in case of solenoid
‌B=nµ0I
‌ Here, ‌‌B∝n
⇒‌‌

Bi

Bf

=‌

ni

nf

⇒‌Bf=Bi‌

nf

ni

=Bi‌

2ni

ni

=2Bi
It will be double.