Question

wha happens to the force acting on current carrying conductor placed in magnetic field when:
(a)current in cunductor increases.
(b)length of the conductor increases.
(c)direction of he current and magnetic field both are reversed.
(d)direction of the current is reversed without changing the direction of magnetic field.

Answer 1

$$\begin{gathered} \mathrm{Expression}\mathrm{for}\mathrm{force}: \\ \mathrm{F}=\mathrm{BIL}\mathrm{sin\theta } \\ \left(\mathrm{a}\right) \\ \mathrm{As}\mathrm{F}\mathrm{is}\mathrm{directly}\mathrm{proportional}\mathrm{to}\mathrm{I},\mathrm{force}\mathrm{acting}\mathrm{on}\mathrm{the}\mathrm{conductor}\mathrm{increases} \\ \left(\mathrm{b}\right) \\ \mathrm{As}\mathrm{F}\mathrm{is}\mathrm{directly}\mathrm{proportional}\mathrm{to}\mathrm{L},\mathrm{force}\mathrm{acting}\mathrm{on}\mathrm{the}\mathrm{conductor}\mathrm{increases} \\ \left(\mathrm{c}\right) \\ \mathrm{No}\mathrm{change}\mathrm{in}\mathrm{the}\mathrm{direction}\mathrm{of}\mathrm{force}\mathrm{since}\mathrm{\theta }=\mathrm{constant} \\ \left(\mathrm{d}\right) \\ \mathrm{Direction}\mathrm{of}\mathrm{force}\mathrm{changes}\mathrm{due}\mathrm{to}\mathrm{variation}\mathrm{in}\mathrm{\theta } \end{gathered}$$