meter

Hello! I have a UNIT-T UT210E clamp meter, which I think it has a problem regarding the current measurements. I will describe the problem below: when I measure current, if the wire is positioned into the center of the clamp (the center marked with the 2 arrows) then it measure 10.16 Aac. But...

Hello! I'm just a begginer student. I found this circuit of a wattmeter that works only with resistors. Can someone explain to me how the 33k resistor give a voltage of 1 mV to 1 Watt? I did not understand why these resistor values has been chosen and why the it measures only in the 33k...