Parker wound a wire around a large iron nail. he then created an electromagnet by connecting the ends of the wire to different batteries. the table shows the current he measured for each electromagnet. which conclusion is best supported by the data? a) electromagnet w is the strongest. b) electromagnet x is weaker than electromagnet z. c) electromagnet y is the strongest. d) electromagnet y is weaker than electromagnet x.

Two kilograms of air within a piston–cylinder assembly executes a carnot power cycle with maximum and minimum temperatures of 800 k and 300 k, respectively. the heat transfer to the air during the isothermal expansion is 60 kj. at the end of the isothermal expansion the volume is 0.4 m3. assume the ideal gas model for the air. determine the thermal efficiency, the volume at the beginning of the isothermal expansion, in m3, and the work during the adiabatic expansion, in kj.