KCET2022PhysicsMagnetic Effects of Current
A metallic rod of mass per unit length 0.5 ~kg ~m ⁻¹ is lying horizontally on a smooth inclined plane which makes an angle of 30^ with the horizontal. A magnetic field of strength 0.25 ~T is acting on it in the vertical direction. When a current I is flowing through it, the rod is not allowed to slide down. The quantity of current required to keep the rod stationary is
Options
- A5.98 ~A
- B14.76 ~A
- C11.32 ~A
- D7.14 ~A
Correct answer
C. 11.32 ~A
Step-by-step solution
Given, magnetic field, B=0.25 ~T Mass per unit length, m l =0.5 ~kg ~m ⁻¹ =30^ The given situation is shown alongside. At balance condition, F 30^ =m g 30^ aligned & B I l 30^ =m g 30^ & B I l 3 2 =m g 1 2 3 B I= ( m l ) g aligned I= ( m l ) g 1 3 B =0.5 10 1 3 0.25 =11.32 ~A