The statement "It is impossible to construct a heat engine which can convert heat directly to work completely" was given by

Q. Assertion :It is impossible to create a heat engine which takes heat energy from a reservoir and completely converts it into work. Reason: Heat energy cannot flow from lower temperature to higher temperature by itself.

Q.

In one complete cycle, a heat engine extracts heat $Q_h$ from a thermal reservoir, does work W and does not eject any heat into the environment. This heat engine is impossible because its operation violates:

Q. Only a part heat energy absorbed can be converted to work by heat engine because:

Q. Assertion (A) : According to the principle of conservation of energy all heat can be converted
into mechanical work
Reason (R) : Due to various losses, it is impossible to convert all heat into mechanical work.

Q.

In one complete cycle, a heat engine extracts heat $Q_h$ from a thermal reservoir, does work W and does not eject any heat into the environment. This heat engine is impossible because its operation violates: