Question

A tester for detecting electric current utilizes some effect of electric current to detect its presence. Which of the following components can be used for this?

Answer 1

Hint: A test light, also known as a test lamp, voltage tester, or mains tester, is a piece of electrical test equipment used to detect whether or not a piece of equipment is powered by electricity. A test light is less expensive and less complicated than a multimeter, yet it may often be used to check for the presence of voltage on a wire. Test lights that are properly constructed have safeguards that protect the operator from receiving an electric shock. Voltage on insulated conductors may be detected using non-contact test lamps.

Complete answer:
A low-cost test light only connects one side of the circuit under test and completes the circuit using stray capacitance and current flowing through the user's body. The gadget might resemble a screwdriver. The tester's tip is placed against the conductor being tested (for instance, it can be used on a wire in a switch, or inserted into a hole of an electric socket). Because a neon lamp requires very little current to illuminate, the circuit may be completed using the user's body capacitance to earth ground.
If the shaft is exposed, the user is exposed to a shock danger, and the tester's internal design offers no protection against short-circuit problems. The user may come into direct metallic contact with the circuit under test if the resistor and light series network fail. Water trapped inside the screwdriver, for example, might cause enough leakage current to shock the operator. Even if the person is not electrocuted by an internal short circuit, the subsequent electric shock may cause a fall or other harm. Because the lamp has no indication below the neon light's striking voltage, it cannot detect some dangerous leaking circumstances.
Direct-current potential cannot be accurately indicated since it relies on capacitance to complete the circuit. When testing a live circuit, a false negative can occur if the user is isolated from ground and capacitively linked to other adjacent live wires. When testing a dead circuit, a false positive can occur if the user is isolated from earth and capacitively coupled to other nearby live wires. False negatives can also happen in brightly light environments, making the neon glow difficult to notice.

Note:
Electrical safety testing is required to guarantee that any product or institution that uses electricity operates safely. Various countries and agencies have established strict regulations for electrical items marketed globally. In most markets, a product must comply with safety requirements set out by safety and standard agencies such as UL, VDE, CSA, BSI, and others.