Figure shows a conducting rod of negligible resistance that can sli...

Figure shows a conducting rod of negligible resistance that can slide on smooth \( U \)-shaped rail made of wire of resistance \( 1 \Omega / \mathrm{m} \). Position of the conducting rod at \( t=0 \) is shown. A time dependent magnetic field \( B=2 t \) tesla is switched on at \( t=0 \).
\( \mathrm{P} \)
W
The magnitude of the force required to move the conducting rod at constant speed \( 5 \mathrm{~cm} / \mathrm{s} \) at the same instant \( t=2 \mathrm{~s} \), is equal to
(a) \( 0.096 \mathrm{~N} \)
(b) \( 0.12 \mathrm{~N} \)
(c) \( 0.08 \mathrm{~N} \)
(d) \( 0.064 \mathrm{~N} \)