Correct option is D
Explanation:
Blackening at both ends of a fluorescent lamp can be caused by several factors:
·
Frequent starting of the fluorescent lamp: Frequent switching on and off of the lamp can cause the electrodes to wear out faster, leading to blackening at the ends.
·
Improper ballast: A malfunctioning or improper ballast can cause improper voltage and current regulation, which can lead to overheating and blackening of the lamp ends.
·
Low or high voltage: Operating the fluorescent lamp at incorrect voltage levels can also cause stress on the lamp components, leading to blackening.
All these factors can contribute to the blackening of a fluorescent lamp, so the correct answer is
"All of the options."
