Which of the following statements is/are correct for a current-carrying solenoid? (i) It can be used to magnetise a piece of soft iron. (ii) It acts like a bar magnet. (iii) The magnetic field lines inside it are concentric circles.

How does the magnetic field at a distance r from an infinitely long wire change if the current is doubled?

The force on a current-carrying conductor in a magnetic field is maximum when _____.

An electron moves vertically downwards into a magnetic field directed towards the right. According to Fleming's Left-Hand Rule, the direction of the magnetic force acting on the electron will be: