The electromagnet in a motor must rotate consistently in just one direction to transform electrical energy into mechanical energy. What causes this
rotation?
A. The terminals of the battery frequently switch from positive to
negative.
B. The commutator frequently reverses the direction of the current in
the loop of wire.
C. The poles of the permanent magnets keep switching between
north and south.
D. The commutator causes the loop of wire to keep turning in one
direction

An incident ray through the focal point of a spherical mirror will: reflect through the center of curvature. reflect back through the focal point. reflect parallel to the principle axis. reflect the same direction as the incident ray.

If a refrigerator is a heat pump that follows the first law of thermodynamics, how much heat was removed from food inside of the refrigerator if it released 380j of energy to the room?

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.