Final answer:
The separation of components in fractional distillation would be affected if the thermometer is positioned 1 cm higher than required, leading to incomplete separation of the two components.
Step-by-step explanation:
The separation of the two components in a fractional distillation would be affected if the thermometer in the distillation apparatus were positioned 1 cm higher than it should have been. The position of the thermometer is crucial in determining the temperature ranges at which the distillate fractions are collected. If the thermometer is higher than it should be, it would measure a lower temperature than the actual boiling point of the lower boiling component A. This would result in incorrect temperature ranges for the collection of the distillate fractions, leading to incomplete separation of the two components.