A tester is used to check the conduction of electricity through two liquids, labelled A and B. It is found that the bulb of the tester glows brightly for liquid A while it glows very dimly for liquid B. We would conclude that
(i) liquid A is a better conductor than liquid B.
When the current flows through the tester then the neon bulb glows as it takes very little current to light. When the current doesn't flow through the tester, the circuit of the tester is not complete and the bulb does not glow. In case of liquid A, the bulb in the tester glows, which means liquid A is a good conductor while the same is not seen in case of liquid B.