i am confused why radiator is placed after the condenser in an automobile. what will happen if we place radiator before the condenser? whether it is related to design or temperature.
The condenser is placed earlier in the flow of air coming from outside as it needs to cool the gas rapidly and the radiator is not affected too much by slightly warmer air.
The A/C condenser only warms the outside air up a small amount as the gas being cooled (refrigerant) only needs a small amount of heat removed to change it to a liquid - while the water in the cooling system has to get rid of much more heat and, only needs to get that water sufficiently cool (somewhere below 88 deg C) to keep the engine under control, so if the incoming air is a few degrees warmer then it does not make a huge difference.
If you place them the other way around the radiator will be fine and the engine at its correct temperature, but the A/C will suffer from poor performance, if it works at all, due to the gas not being cooled sufficiently.