Define the term efficiency of a machine. Give two reasons for a machine not be 100% efficient?

Define thermal efficiency of a heat engine.

A machine raises a laod a 750 N through a height of 16 m in 5 s.Calculate: (i)the energy spent by the machine , (ii)the power of the machine if it is 100 % efficient.

How is mechanical advantage related with velocity ratio for an actual machine ? State whether the efficiency of such a machine is equal to 1, les sthan 1 or more than 1.

State the principle of working of a transformer. (b) Define efficiency of a transformer. (c ) State any two factors that reduce the efficiency of a transformer. (d) Calculate the current drawn by the primary of a 90% efficient transformer which steps down 220 V to 22 V , if the output resistance is 440 Omega .

With reference to the term mechanical advantage, velocity ratio and efficiency of a machine, name and define the term that will not change for a machine of a given design.

Give three reasons for the loss in energy in a machine.

Even carnot heat engine cannot give 100% efficiency. Explain why OR can you design a heat engine of 100% efficiency? Explain ypur answer. OR A heat engine with 100% efficiency is only a theoretical possibility. Explain.

Under what conditions can a Carnot engine have 100% efficiency?

(a) State the relationship between mechanical advantage, velocity ratio and efficiency. (b) Name the term that will not change for a machine of a given design.