Question

Assertion : A tube light emits white light.
Reason : Emission of light in a tube takes place at a very high temperature.

• A. if both assertion and reason are true and the reason is the correct explanation of the assertion
• B. if both assertion and reason are true and the reason is not the correct explanation of the assertion
• C. if assertion is true but reason is false
• D. if both assertion and reason are false statements

Answer 1

Answer: (C)

Tube light is basically a fluorescent lamp that uses electricity to excite mercury vapour in argon or neon gas, resulting is plasma that produces short-wave ultraviolet light. This light then causes a phosphor to fluorescence producing visible light. The emission takes place at low pressure and not at high temperature, since thermionic emission takes place.