किसने यह खोजा या सुझाव दिया था कि चुंबकीय क्षेत्र में रखे जाने पर धारावाही चालक पर एक बल कार्य करता है जिससे वह गति करता है?

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: