Question

Which of the following devices can be used to detect a weak current?
A) use of an electric bulb in a tester.
B) use of LED in tester
C) a tester using magnetic effects of current
D) both (B) and (C)

Answer 1

Hint: The term "weak current" refers to DC voltages of less than 24 volts, such as audio, video, network, and telephone connections. Household electrical appliances (cable line) and audio equipment (output lines) such as telephones, computers, and televisions are examples of weak electrical equipment.

Complete Step By Step Answer:
The weak voltage is known as weak current, and the difference between it and strong power stems mostly from the difference in application. Weak electricity is utilised for information transmission while strong electricity is used as a power source. Strong power indicates that the AC voltage is more than 24 volts. The voltage in the home, such as electric lights and plugs, is 110V-220V. Lighting fixtures, electric water heaters, heaters, freezers, televisions, air conditioners, and audio equipment are all examples of powerful electrical equipment found in domestic electrical appliances.
Weak neutral current interactions are one of the weak force's ways of interacting with subatomic particles. The Z boson mediates these interactions. The discovery of weak neutral currents was a crucial step toward the electroweak force's unification, and it led to the discovery of the W and Z bosons.
Even with a modest electric current flowing through it, an LED shines. The deflection of the magnetic needle may also be detected, even if the current is modest. As a result, a tester that uses LEDs or magnetic current effects can be utilised to detect a weak current.
Hence option D is correct.

Note:
When current passes through a light-emitting diode (LED), it produces light. Electrons recombine with electron holes in the semiconductor, producing energy in the form of photons. The energy required for electrons to bridge the semiconductor's band gap determines the hue of light (equivalent to the energy of photons).