Question 3 of 16 Which statement correctly describes magnetic field lines?
A. They form loops by joining north pole to south pole.
B. They are parallel with one another.
C. They show the direction a south pole will point.
D. They form loops by joining positive charge to negative charge.

An air standard cycle with variable specific heats is executed in a closed system and is composed of the following four processes. 1-2 isentropic compression 100 kpa and 22°c to 600 kpa 2-3 v=constant heat addition to 1500 k 3-4 isentropic expansion to 100 kpa 4-1 p=constant heat rejection to initial state (a) show the cycle on p-v and t-s s (b) calculate the net work output per unit mass (409 kj/kg) (c) determine the thermal efficiency (47.9%)