In Nepal and Tibet, electricity comes from the mains in your hotel at 220 volts with a European style two-round-pin plug. There is an automatic converter in most North American appliances which will allow you to plug 110 volt items into the 220 volt electricity in Nepal and Tibet. Please be sure to read the back of your appliance or charger to make sure it does this conversion automatically.
If you are in a hotel or village in Tibet, you may have to plug into the ceiling light fixture and it's possible to buy a simple bayonet adapter in Kathmandu, Zhangmu, etcetera. Warning, there are power spikes and surges which may damage your appliance.