A technician A says that a voltmeter can be used to monitor the output signal of an optical sensor. Technician B says that optical sensors should be tested with an oscilloscope because of the sensor's speed. Which technician is correct?

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

Idon’t quite understand this problem

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.