A straight wire AB of mass 40 g and length 50 cm is suspended by a pair of flexible leads in uniform magnetic field of magnitude 0 . 40 T as shown in the figure. The magnitude of the current required

Question

A straight wire AB of mass 40 g and length 50 cm is suspended by a pair of flexible leads in uniform magnetic field of magnitude 0 . 40 T as shown in the figure. The magnitude of the current required in the wire to remove the tension in the supporting leads is _____ A . (Take g = 10 m s - 2 .

TestHub · Accepted Answer

The formula to calculate the magnetic force on the conductor is given by
$F_{B} = I L B . . . (1)$
The formula to calculate the gravitational force on the conductor is given by
$F_{G} = m g . . . (2)$
Equate both the equations and simplify to obtain the required current through the conductor.
$\begin{array}{rcl} I L B & = & m g \\ \Rightarrow & I = \frac{m g}{L B} . . . (3) \end{array}$
Substitute the values of the known parameters into equation (3) to calculate the required current through the conductor.
$\begin{array}{rcl} I & = & \frac{\frac{40}{1000} kg \times 10 m s^{- 2}}{0.5 m \times 0.40 T} \\ = & 2 A \end{array}$

Physics - Magnetism Question with Solution | TestHub

Doubts & Discussion