Question

A current-carrying wire in a magnetic field is subjected to a magnetic force. If the current in the wire is quadrupled. Find out the change in magnetic force acting on the wire?

• A. It is quartered
• B. It is halved
• C. It is unchanged
• D. It is doubled
• E. It is quadrupled

Answer 1

The correct option is E It is quadrupled

Magnetic force on the wire $F=IBl$

Now the current in the wire is quadrupled i.e $I^{\prime }=4I$

Thus new magnetic force $F^{\prime }=I^{\prime }Bl=\left(4I\right)Bl=4F$

Hence the force also gets quadrupled.