The gap between any two rails, each of length 'l' laid on a railway track equals x at 27°C. When the temperature rises to 40°C, the gap closes up. The coefficient of linear expansion of material of the rail is 'alpha'. The length of a rail at 27°C will be

The gap between any two rails, each of length 'l' laid on a railway

1.	The gap between any two rails, each of length 'l' laid on a railway track equals x at 27°C. When the temperature rises to 40°C, the gap closes up. The coefficient of linear expansion of material of the rail is 'alpha'. The length of a rail at 27°C will be
Answer» `(x)/( 2 B alpha)` `( x)/( 13 alpha)` `( 2X)/( 13 alpha) ` None Answer :B