Which of the following statements about electric wires is NOT true?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → The third is the earth wire that has pink insulation and this is connected to a metallic body deep inside earth. It is used as a safety measure to ensure that any leakage of current to a metallic body does not give any severe shock to a use.
Option 1: “The wire of black insulation, is a neutral wire.” This statement is correct. In domestic wiring, the black wire is commonly used as the neutral wire.
Option 2: “In our houses we receive AC electric power of 220 V with a frequency of 50 Hz. One of the wires in this supply is with red insulation, called live wire.” This statement is correct. Domestic electric supply in India is approximately 220 V with a frequency of 50 Hz, and the red wire is generally the live wire.
Option 3: “The third is the earth wire that has pink insulation and this is connected to a metallic body deep inside earth. It is used as a safety measure to ensure that any leakage of current to a metallic body does not give any severe shock to a use.” This statement is incorrect. The earth wire is generally green (or green-yellow), not pink. It is connected to a metal plate or pipe buried deep inside the earth for safety purposes.
Option 4: “The electric wires used in houses are generally made of copper.”This statement is correct because copper is a very good conductor of electricity.