Give two statements of second law of thermodnamics.

Explanation

Claussius statement
"It is impossible for a self acting machine to transfer heat from a lower temperature to a higher temperature, without the help of external agent."
Kelvin Planck statement
"It is impossible to get a continuous supply of work, by cooling a body to a temperature lower than that of the coldest of its surroundings." 
Equivalence of two statements
  Suppose we have an engine, which gives continuous supply of work when it is cooled below the temperature of its surrounding. This is violation of kelvin statement. Now if the work done by the engine is used to drive a dynamo, which produces current and this current produces heat in a coil immersed in hot water. Then we have produced a machine which causes the flow of heat from cold body to hot body without the help of any external agent. This is the violation of Claussius statement. Hence both statements are equal.