If the Ac main supply alternator speed increased from 110V/50hz to110V/100hz, then what would be the effect on home appliances.

In order to answer this question breifly , i will consider some effects of increasing the frequency :

1-Increasing the frequency above the design (nominal) operating frequency will reduce conductors ampacity due to skin effect which is usually ignored in low frequncies (50/60Hz).

2-Increasing the frequency will saturate transformers cores due to increasing number of magnetic flux cycles , i.e. , increasing transformers losses which yeilds to transformers burn.

3- Motors (A/C units , Refrigerators , Water Pumps , etc.)  will be affected directly by increasing motor speed which will distroy motor bearings (mechanical damage) or burns motor windings (electrical damage).

4-electronic based devices (Computers , chargers , etc.) mostly will be burn ed due to heat effect in thier electronic parts unless he device it self is protected from over frequncy .

5-in General , All international standards & electric utilities are not allowing frequency deviation more than +/-0.5Hz ue to the major effect of frequncy of househeld appliances .

Regards,

Saqer Ali 

Due to increase in frequency, speed will increase. But I*I*R losses will add heating effect. If the electrical appliance has cooling fans, cooling effect will increase due to increased speed. There will be no increase in I value, but mechanical friction effect will wear the bearing faster as compard to50Hz.

it would be very distructive due to changes in temperature which would be cause by increase of speed in electrical machine.