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A metel rod of the length 10cm and a rec...

A metel rod of the length 10cm and a rectangular cross-section of 1 cm xx `1//2` cm is connected to a battery across opposite faces. The resistance will be

A

maximum when the battery is connected across `1cm(1)/(2)cm` faces

B

maximum when the battery is connected across `10cmxx1cm` faces

C

maximum when the battery is connected across `10cmxx(1)/(2)cm` faces

D

same irrespective of the three faces

Text Solution

Verified by Experts

The resistance of wire is given by
`R=rho(l)/(A)`
for greater value of `R`, l must be higher and A should be lower and it is possible only when the battery is connected across `1cmxx((1)/(2))cm` (area of cross-section A).
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