An engine has an efficiency of 1 / 6 . When the temperature of sink is reduced by 62^ C , its efficiency is doubled. Temperatures of the source is:

Step-by-step solution

Efficiency of an engine, ( =1- T₂ T₁ ) where (T₁ ) is the temperature of the source and (T₂ ) is the temperature of the sink. ( 1 6 =1- T₂ T₁ ) or, ( T₂ T₁ = 5 6 ) ( 2 1 6 =1- (T₂-62 ) T₁ ) or, ( 1 3 =1- (T₂-62 ) T₁ ) or, ( 2 3 = T₂-62 T₁ ) or, (2 T₁=3 T₂-186 ) or, (2 T₁=3 [ 5 6 ] T₁-186 ) [using (i)] ( [ 5 2 -2 ] T₁=186 ) or, ( T₁ 2 =186 ) or, (T₁=372 ~K =99^ C ).