A metal rod of length 10 cm and a rectangular cross-section of 1 cm × 1/2 cm is connected to battery across opposite faces. The resistance will be a) maximum when the battery is connected across 1 cm × 1/2 cm faces b) maximum when the battery is connected across 10 cm × 1 cm faces c) maximum when the battery is connected across 10 cm × 1/2 cm faces d) same irrespective of the three faces
Correct option is A) length =10cm rectangular cross section =1cm×21cm. The resistance will be R=ρ×Al R α Al For maximum resistance A should be minimum and l should be longer. So option A
