Technician A says modern thermostats remain closed until coolant temperature is as high as 180°F (82°C). Technician B says once the engine is completely warmed up, the thermostat has no effect on cooling system operation. Who is right?

A late-model hybrid vehicle with a motor-driven compressor has poor cooling. Technician A says that the best way to check system operation is with a scan tool. Technician B says that using an electronic leak detector may damage the motor insulation. Who is right? 

Technician A says R-134a has no effect on global warming. Technician B says R-134a has no effect on the ozone layer. Who is right?

All of the following is used to flush a refrigeration system, except:

En la figura, se muestra un conductor formado por dos tramos dentro de una región donde existe un campo magnético uniforme de magnitud , dirigido hacia dentro del plano de la página. El conductor está compuesto por un primer tramo vertical de longitud y un segundo tramo inclinado de longitud , el cual forma un ángulo de

What two devices are never found on the same refrigeration system?

Technician A says if the pressure is held constant, a substance will have different vaporizing and condensing temperatures. Technician B says higher pressures cause higher boiling points. Who is right?

Technician A says heat always travels from a warmer object to a colder one. Technician B says when all objects in an area are at the same temperature, no heat transfer will occur. Who is right?

En la figura, se muestra un conductor recto por el cual circula una corriente I que sale del plano de la página. El conductor se encuentra inmerso en un campo magnético uniforme

Una partícula cargada es acelerada desde el reposo por una diferencia de potencial