Saved Bookmarks
| 1. |
A very small circular loop of radius a is initially (at t = 0) coplanar and concentric with a much larger fixed circular loop of radius b. A constant current I flows in the larger loop. The smaller loop is rotated with a constant angular speed omega about the common diameter. The emf induced in the smaller loop as a function of time t is |
|
Answer» `(pi a^(2)mu_(0)I)/(2B)omega cos (omega t)` The magnetic field at the common centre due to the current in LARGER loop is `B_(l)=(mu_(0))/(4pi)(2pi I)/(b)=(mu_(0)I)/(2b)` where SUBSCRIPT l refers to larger loop. The magnetic flux linked with the smaller loop at time t is `phi_(s)=B_(l)A_(s)cos omega t` where subscript s refers to smaller loop. `phi_(s)=(mu_(0)I)/(2b)pi a^(2)cos omega t` The emf induced in the smaller loop is `epsilon_(s)=-(d PHI)/(dt)=-(d)/(dt)((mu_(0)I pi a^(2))/(2b)cos omega t)=(mu_(0)I pi a^(2))/(2b) omega sin omega t` 
|
|