A disc of radius R is rolling without sliding on a horizontal surface with a velocity of center of mass v and angular velocity omega in a uniform magnetic field B which is perpendicular to the plane of the disc as shown in Fig. 3.179. O is the center of the disc and P, Q, R, and S are the four points on the disc. Which of the following statements is true?

A disc of radius R is rolling without sliding on a horizontal surface

1.	A disc of radius R is rolling without sliding on a horizontal surface with a velocity of center of mass v and angular velocity omega in a uniform magnetic field B which is perpendicular to the plane of the disc as shown in Fig. 3.179. O is the center of the disc and P, Q, R, and S are the four points on the disc. Which of the following statements is true?
Answer» (a) Due to translation, induced emf ACROSS `PS = Bvr` (b) Due to translation, induced emf across `QS = 0` ( c) Due to translation, induced emf across `RO = 0` (d) Due to translation, induced emf across `OQ = Bvr` SOLUTION :(a,b,c,d): Due to rotaion, `emf= (Br^(2)omega)/(2)` Due to translation INDEED emf `= Bvr` where `r` is the SEPARATION.

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