Objective: How can I check if an appliance is properly receiving power from an outlet?

Which of the following solutions is more sound in terms of naive physics reasoning?

Choose from:
(I) Find and locate other appliances electronics that use an outlet as a power source. Connect each appliance and electronics to the outlet, and see if they power on or charge.;
(II) Use a voltmeter or a multimeter tool and check if the outlet is properly supply power to an appliance. If no voltage is recorded from an outlet, then utilize another outlet.;
(II)