'2- Consider a chemical tank for which there are three variables to be monitored These variables are level, pressure, temperature. The circuit has to be designed such that an alarm is sounded when certain combinations of conditions of the variables OCcur. The alarm will sound if 1. The liquid level is low and the pressure is high: 2. The liquid level is high and the temperature is high: 3 . High liquid level with low temperature and high pressure_'