Final answer:
A test light is an instrument with a bulb and test leads used for detecting the presence of voltage in a circuit. It's different from a voltmeter, multimeter, or ammeter, which are used to measure voltage, a range of electrical parameters, and current, respectively. The correct option in the final answer is a test light.
Step-by-step explanation:
A test light is a test instrument with a bulb that is connected to two test leads to give a visual indication of when voltage is present in a circuit. Unlike a voltmeter, which measures the potential difference between two points in an electrical circuit, or a multimeter which can measure voltage, current, and resistance, a test light is a simpler device primarily used for detecting the presence of voltage. An ammeter, on the other hand, measures the rate of flow of electric current in a circuit and needs to be connected in series with the circuit component being tested.
Analog meters, such as voltmeters and ammeters, use a needle movement over a marked gauge for readouts, as opposed to digital meters that give direct numeral values. The operation of these devices is often based on the principles of Ohm's law, where V=IR, which establishes the relationship between voltage (V), current (I), and resistance (R).
In conclusion, the correct option for a test instrument with a bulb used to indicate voltage is the test light. This device provides a convenient and quick way to check for voltage in a circuit without quantifying the exact voltage level.