The correct answer is Both A and B. Concept: Conductivity in aqueous solutions: It is a measure of the ability of water to conduct an electric current. The more ions there are in the solution, the higher its conductivity. Electrolyte: Electrolytes are salts or molecules that ionize completely in solution. As a result, electrolyte solutions readily conduct electricity. A strong electrolyte is one where many ions are present in the solution and a weak electrolyte is one where few ions are present. Non-electrolytes: They do not dissociate into ions in solution. Therefore, they do not conduct electricity. Explanation: The tester can be used to determine whether a liquid allows an electric current to pass through it or not. Before using the tester, We will also test whether it is working or not When the fluid between the two ends of the tester allows an electric current to flow through it, the circuit of the tester is complete. A current flows through the circuit, and the bulb lights up. When a liquid does not allow the electric current to flow through it, the circuit of the tester is broken and the bulb does not light up. Even if the liquid is a conductor, it is possible that the bulb will not light in some cases, indicating that the electric current in the tester is very weak. Since the bulb in the tester did not glow - (A) The circuit of tester remained incomplete - True (B) The current through the tester was too weak - True