Magnetic field produced by an infinitely long straight current

[nanas]

my guy just solved a doubt I had for over a week in less than 10 min, just like that 😂😂😂😂

[manavpatel]

isnt it dL cross r hat instead of I cross r hat/

[spurti]

I have question why we are using r unit vector instead of r vector??

[Bhawna]

Which country ? M also physics mentor #BHAWNAPHYSICSCLASS ... but never seen these kind of derivative part to be learnt in foreign country.