A substance which radiates light when heated to a high temperature is said to be

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Q: 53 (CDS-I/2006)
A substance which radiates light when heated to a high temperature is said to be

question_subject: 

Science

question_exam: 

CDS-I

stats: 

0,8,19,10,8,9,0

keywords: 

{'luminescent': [0, 0, 1, 0], 'fluorescent': [0, 0, 2, 0], 'incandescent': [0, 0, 1, 0], 'phosphorescent': [0, 0, 1, 0], 'light': [16, 4, 34, 62], 'high temperature': [0, 2, 3, 11], 'substance': [2, 1, 7, 7]}

The term "radiates light" refers to the emission of light energy from a substance. When a substance is heated to a high temperature, it begins to emit light, a phenomenon known as incandescence.

Option 1: Luminescent refers to the ability of a substance to emit light without heating. It includes both fluorescence and phosphorescence, but heating is not necessary for luminescence to occur.

Option 2: This is the correct answer. Incandescence specifically refers to the emission of light when a substance is heated to a high temperature.

Option 3: Fluorescence is the emission of light by a substance when it absorbs light of a shorter wavelength and re-emits light of a longer wavelength almost immediately. Fluorescence does not require high temperatures.

Option 4: Phosphorescence is similar to fluorescence, but with a delay in the emission of light. After exposure to light, a phosphorescent substance continues to emit light for some time even after the light source is removed. Phosphorescence does not require high temperatures.

In conclusion, the correct answer is option 2 (Incandescent), as it specifically refers to the emission of light from a substance when heated to a high temperature.