How does technology in the use of energy make life easier?

What is arcing ground? What other inventions helped make web perfecting press possible? How much steel work progress one steel fixer per day? What type of metal used in bearings and bushings? What simple machines used to raise and lower things? What is the opposite of constructed? In the potentiometer resistance increases gradually then why fan speed increases? Why floating neutral in a three phase supply is undesirable? Can you charge a 120 volt DC battery pack with 120 volt ac current? What is the compressive strength of refractory bricks? What are digital instruments in mechanical engineering? What is the difference between landline phones and mobile phones? Algorithm to find factorial using functions? What is static code analysis used for? Game source in openGL WITH C? What are some examples of complex systems? Can you bleed a combi boiler? What are the input required to form a test plan? In order for a 30 volt 90 watt lamp to work properly in a 120 volt supply the required series resister in ohm is? How does thermal expansion of steel compare to aluminum?