A test charge experiences a force of 1.66 ×10−9 N at a point where the electric field intensity is exactly 0.000347 N/C. Which value best represents the size of the test charge?

A. 5.76 x 10-13 C
B. 4.78 x 10-6 C
C. 4730 C
D. 56700 C

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.