A conducting wire XY of mass $m$ and negligible resistance slides smoothly on two parallel conducting wire as shown in the fig. The closed circuit has a resistance R due to AC. AB and CD are perfect conductors. There is a magnetic field $B = B (+) \hat {k}$ . Is there a decrease in kinetic energy of XY equalling the heat lost in R ?

Question

 

(a) No, there is no decrease in kinetic energy
(b) Yes, there is a decrease in kinetic energy
(c) Yes, there is a decrease in kinetic energy which is equal to the heat lost in R
(d) Yes, there is a decrease in kinetic energy, but that is not equal to the heat energy lost in R