Question

Time varying magnetic filed is present in a circular region of radius R. Match the proper entries from column-2 to column-1 using the codes given below the columns,
`{:("Column I",,"Column II"),("(P) An unsteady magnetic field",,"(1) Electric field is perpendicular to the length of rod "),((Q) "Induced electric field at a point within magnetic field (r gtR)",,(2) r/2 (dB)/(dt)),("(R)Induced electric field at a point out side the magnetic field (r lt R)",,(3)(R^(2))/(2r)(dB)/(dt)),((S)"If a rod is placed along the diameter of the magnetic field",,"(4) induced electric field"):}`
A. `{:(,P,Q,R,S),((A),3,2,1,4):}`
B. `{:(,P,Q,R,S),((B),2,1,3,4):}`
C. `{:(,P,Q,R,S),((C),4,2,1,3):}`
D. `{:(,P,Q,R,S),((D),4,2,3,1):}`

Answer 1

Explanation :
time varying magnetic field produced electric field unknown as induced electric field.
So `(P) to (4)`
for flt R
`oint E.DI=-(AdB)/(dt)`
`E 2pir=-pir^(2)(dB)/(dt)`
`E=-r/2 (dB)/(dt)`
So, `(Q)to(2)`
For rgt R
`E 2p r=-piR^(2) (dB)/(dt) s s, E=-(R^(2))/(2r)(dB)/(dt)`
So `(R)to(3)`
If rod ris placed along the diameter of magnetic field, then electric field is perpendicular to length of rod.