Question

Which of the following instruments can detect the presence of a voltage, but not the voltage level?

Answer 1

A neon 'tester' is just a little neon light bulb that glows orange
when it touches a point of more than maybe 90 volts or so. 
When it lights up, you can tell that it's touching a live point, but
you can't tell from the brightness of the glow what the actual
voltage is at that point.

Answer 2

Neon Circuit Tester(A). Multi tests both, Watt tests the voltage level and clamp is the same as a watt meter