www. Mechanical energy is supplied to a d.c. generator at the rate of 3500 J/s. The generator delivers 28.7 A at 120 V (i) What is the percentage efficiency of the generator? (ii) How much energy is lost per minute of operation?

Create a short essay based on your own understanding and opinion about the question, “How does a dc generator work?”. Minimum of 150 words.

The field winding of a d.c. motor is connected to a 110V supply. At a temperature of 18°C, the current drawn is 0.575 A. After running the machine for some time the current has fallen to 0.475 A, the voltage remaining unchanged. Calculate the temperature of the winding under the new conditions, assuming that the temperature coefficient of resistance of copper is 0.004 26/°C at 0°C.